Outcomes of Primary Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction Patients With Previous Coronary Bypass Surgery

ObjectivesThis study sought to determine the contemporary clinical characteristics and outcomes of patients with ST-segment elevation myocardial infarction (STEMI) and previous coronary artery bypass graft (CABG), including those with a saphenous vein graft culprit lesion.BackgroundThe outcome of STEMI patients with previous CABG is reported to be inferior to those without previous CABG, but limited data is available from the primary percutaneous coronary intervention era.MethodsData was extracted from a large, regional STEMI system’s prospective database, which contained 3,542 unique STEMI episodes from March 4, 2003 through April 22, 2012.ResultsPrevious CABG was present in 249 patients (7%). Despite higher comorbidity, patients with versus those without previous CABG had similar in-hospital (4.8% vs. 5.2%; p = 0.82) and 1-year (10.8% vs. 9.1%; p = 0.36) mortality, but 5-year (24.9% vs. 14.2%; p < 0.001) mortality was higher. Patients with previous CABG have similar door-to-balloon times. The culprit vessel was the saphenous vein graft in 84 patients (34%), a native vessel in 104 (42%), with no clear culprit in 59 (24%). The left internal mammary artery graft was not a culprit in any patient. Mortality at 30 days (8.3% vs. 3.9% vs. 1.7%, p = 0.19) and 1 year (14.3% vs. 9.0% vs. 6.8%; p = 0.35) was higher (but not statistically) with a saphenous vein graft culprit and was equivalent at 5 years (25.0% vs. 26.0% vs. 20.3%; p = 0.71).ConclusionsPatients with previous CABG treated in a regional STEMI system have similar outcomes as patients without previous CABG, although 5-year mortality is higher. The most common culprit location was a native vessel (42%). Outcomes have improved significantly compared with historical reports.     

Mechanisms of Atherothrombosis and Vascular Response to Primary Percutaneous Coronary Intervention in Women Versus Men With Acute Myocardial Infarction: Results of the OCTAVIA Study

ObjectivesThis study sought to assess in vivo sex differences in the pathophysiology of ST-segment elevation myocardial infarction (STEMI) and vascular response to primary percutaneous coronary intervention (PCI).BackgroundThere is no consensus on whether differences in the pathophysiology of STEMI and response to primary PCI between women and men reflect biological factors as opposed to differences in age.MethodsIn this prospective, multicenter study, 140 age-matched men and women with STEMI undergoing primary PCI with everolimus-eluting stent were investigated with intravascular optical coherence tomography, histopathology-immunohistochemistry of thrombus aspirates, and serum biomarkers. Primary endpoints were the percentages of culprit plaque rupture at baseline and everolimus-eluting stent strut coverage at 9-month follow-up as determined by optical coherence tomography.ResultsMen and women had similar rates of plaque rupture (50.0% vs. 48.4%; risk ratio [RR]: 1.03; 95% confidence interval [CI]: 0.73 to 1.47; p = 0.56). Nonruptured/eroded plaques comprised 25% of all cases (p = 0.86 in men vs. women). There were no sex differences in composition of aspirated thrombus and immune and inflammatory serum biomarkers. At 9 months, women had similar strut coverage (90.9% vs. 92.5%; difference in medians: RR: 0.2%; 95% CI: –0.4% to 1.3%; p = 0.89) and amount of in-stent neointimal obstruction (10.3% vs. 10.6%; p = 0.76) as men did. There were no sex differences in clinical outcome either at 30-day or 1-year follow-up.ConclusionsIn patients presenting with STEMI undergoing primary PCI, no differences in culprit plaque morphology and factors associated with coronary thrombosis were observed between age-matched men and women. Women also showed similar vascular healing response to everolimus-eluting stents as men did. (Optical Coherence Tomography Assessment of Gender Diversity In Primary Angioplasty: The OCTAVIA Trial [OCTAVIA]; NCT01377207)     

Randomized Comparison of Everolimus-Eluting Stents and Sirolimus-Eluting Stents in Patients With ST Elevation Myocardial Infarction: RACES-MI Trial

ObjectivesThe aim of the current study was to compare everolimus-eluting stents (EES) with sirolimus-eluting stents (SES) in patients undergoing primary angioplasty.BackgroundDrug-eluting stents may offer benefits in terms of repeat revascularization. However, as shown for first-generation drug-eluting stents, they may be counterbalanced by a potential higher risk of stent thrombosis, especially among patients with ST-segment elevation myocardial infarction (STEMI). No data have been reported so far on the long-term benefits and safety of the new generation of drug-eluting stents in STEMI.MethodsConsecutive STEMI patients admitted within 12 h of symptom onset and undergoing primary angioplasty and stent implantation at a tertiary center with 24-h primary percutaneous coronary intervention capability were randomly assigned to SES or EES. The primary endpoint was a major adverse cardiac event at 3-year follow-up. The secondary endpoints were death, reinfarction, definite or probable stent thrombosis, and target vessel revascularization at 3-year follow-up. No patient was lost to follow-up.ResultsFrom April 2007 to May 2009, 500 patients with STEMI were randomized to EES (n = 250) or SES (n = 250). No difference was observed in terms of baseline demographic and clinical characteristics between the groups. No difference was observed between the groups in terms of number of implanted stents per patient or total stent length. However, a larger reference diameter was observed with SES (3.35 ± 0.51 mm vs. 3.25 ± 0.51 mm, p = 0.001), whereas patients randomized to EES more often received glycoprotein IIb/IIIa inhibitors (54.4% vs. 42.4%, p = 0.006). Follow-up data were available in all patients (1,095 ± 159 days). No significant difference was observed between EES and SES in major adverse cardiac events (16% vs. 20.8%, adjusted hazard ratio [HR]: 0.75 [95% confidence interval (CI): 0.5 to 1.13], p = 0.17), cardiac death (4.4% vs. 5.6%, adjusted HR: 0.77 [95% CI: 0.35 to 1.71], p = 0.53), recurrent MI (6.4% vs. 10%, adjusted HR: 0.62 [95% CI: 0.33 to 1.16], p = 0.13), and target vessel revascularization (4.8% vs. 4.8%, adjusted HR: 1.00 [95% CI: 0.45 to 2.32], p = 0.99). However, EES was associated with a significant reduction in stent thrombosis (1.6% vs. 5.2%, adjusted HR: 0.3 [95% CI: 0.1 to 0.92], p = 0.035).ConclusionsThis study shows that among STEMI patients undergoing primary angioplasty, EES has similar efficacy as SES, but is associated with a significant reduction in stent thrombosis. (Randomized Comparison of Everolimus Eluting Stents and Sirolimus Eluting Stent in Patients With ST Elevation Myocardial Infarction [RACES-MI]; NCT01684982)     

Randomized Comparisons Between Different Stenting Approaches for Bifurcation Coronary Lesions With or Without Side Branch Stenosis

ObjectivesThis study sought to evaluate the optimal percutaneous coronary intervention techniques using drug-eluting stents for bifurcation coronary lesions.BackgroundThe optimal bifurcation stenting technique needs to be evaluated.MethodsThe trial included 2 randomization studies separated by the presence of side branch (SB) stenosis for patients having non–left main bifurcation lesions. For 306 patients without SB stenosis, the routine final kissing balloon or leave-alone approaches were compared. Another randomization study compared the crush or single-stent approaches for 419 patients with SB stenosis.ResultsBetween the routine final kissing balloon and leave-alone groups for nondiseased SB lesions, angiographic restenosis occurred in 17.9% versus 9.3% (p = 0.064), comprising 15.1% versus 3.7% for the main branch (p = 0.004) and 2.8% versus 5.6% for the SB (p = 0.50) from 214 patients (69.9%) receiving 8-month angiographic follow-up. Incidence of major adverse cardiac events including death, myocardial infarction, or target vessel revascularization over 1 year was 14.0% versus 11.6% between the routine final kissing balloon and leave-alone groups (p = 0.57). In another randomization study for diseased SB lesions, 28.2% in the single-stent group received SB stents. From 300 patients (71.6%) receiving angiographic follow-up, between the crush and single-stent groups, angiographic restenosis rate was 8.4% versus 11.0% (p = 0.44), comprising 5.2% versus 4.8% for the main branch (p = 0.90) and 3.9% versus 8.3% for the SB (p = 0.12). One-year major adverse cardiac events rate between the crush and single-stent groups was 17.9% versus 18.5% (p = 0.84).ConclusionsAngiographic and clinical outcomes were excellent after percutaneous coronary intervention using drug-eluting stents with any stent technique for non–left main bifurcation lesions once the procedure was performed successfully.     

Effect of Sex Differences on Invasive Measures of Coronary Microvascular Dysfunction in Patients With Angina in the Absence of Obstructive Coronary Artery Disease

ObjectivesThis study investigated sex differences in coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) in patients with angina in the absence of obstructive coronary artery disease.BackgroundCoronary microvascular dysfunction is associated with worse long-term outcomes, especially in women. Coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) are 2 methods of assessing the coronary microcirculation.MethodsWe prospectively enrolled 117 women and 40 men with angina in the absence of obstructive coronary artery disease. We performed CFR, IMR, fractional flow reserve, and quantitative coronary angiography in the left anterior descending artery. Coronary flow was assessed with a thermodilution method by obtaining mean transit time (T_mn) (an inverse correlate to absolute flow) at rest and hyperemia.ResultsAll patients had minimal atherosclerosis by quantitative coronary angiography (% diameter stenosis: 23.2 ± 12.3%), and epicardial disease was milder in women (fractional flow reserve: 0.88 ± 0.04 vs. 0.87 ± 0.04; p = 0.04). IMR was similar between the sexes (20.7 ± 9.8 vs. 19.1 ± 8.0; p = 0.45), but CFR was lower in women (3.8 ± 1.6 vs. 4.8 ± 1.9; p = 0.004). This was primarily due to a shorter resting T_mn in women (p = 0.005), suggesting increased resting coronary flow, whereas hyperemic T_mn was identical (p = 0.79). In multivariable analysis, female sex was an independent predictor of lower CFR and shorter resting T_mn.ConclusionsDespite similar microvascular function in women and men by IMR, CFR is lower in women. This discrepancy appears to be due to differences in resting coronary flow between the sexes. The effect of sex differences should be considered in interpretation of physiological indexes using resting coronary flow.     

Outcomes After Percutaneous Coronary Intervention With Stents in Patients Treated With Thoracic External Beam Radiation for Cancer

ObjectivesThe aim of this study was to assess outcomes after percutaneous coronary intervention (PCI) with stents in patients treated with thoracic external beam radiation therapy (EBRT).BackgroundThoracic EBRT for cancer is associated with long-term cardiotoxic sequelae. The impact of EBRT on patients requiring coronary stents is unclear.MethodsWe analyzed outcomes after PCI in cancer survivors treated with curative thoracic EBRT before and after stenting between 1998 and 2012. Reference groups were propensity-matched cohorts with stenting but no EBRT. Primary endpoint was target lesion revascularization (TLR), a clinical surrogate for restenosis. Secondary endpoints included myocardial infarction (MI) and cardiac and overall mortality.ResultsWe identified 115 patients treated with EBRT a median 3.6 years after stenting (group A) and 45 patients treated with EBRT a median 2.2 years before stenting (group B). Long-term mean TLR rates in group A (3.2 vs. 6.6%; hazard ratio: 0.6; 95% confidence interval: 0.2 to 1.6; p = 0.31) and group B (9.2 vs. 9.7%; hazard ratio: 1.2; 95% confidence interval: 0.4 to 3.4; p = 0.79) were similar to rates in corresponding control patients (group A: 1,390 control patients; group B: 439 control patients). Three years post-PCI, group A had higher overall mortality (48.6% vs. 13.9%; p < 0.001) but not MI (4.8% vs. 4.3%; p = 0.93) or cardiac mortality (2.3% vs. 3.6%; p = 0.66) rates versus control patients. There were no significant differences in MI, cardiac, or overall mortality rates in group B.ConclusionsThoracic EBRT is not associated with increased stent failure rates when used before or after PCI. A history of PCI should not preclude the use of curative thoracic EBRT in cancer patients or vice versa. Optimal treatment of cancer should be the goal.     

The Association of Previous Revascularization With In-Hospital Outcomes in Acute Myocardial Infarction Patients: Results From the National Cardiovascular Data Registry

ObjectivesThe aim of this study was to compare outcomes of ST-segment elevation myocardial infarction (STEMI) patients with a history of coronary artery bypass graft surgery (CABG), previous percutaneous coronary intervention (PCI), or no previous revascularization undergoing primary PCI.BackgroundLimited data exist regarding door-to-balloon times and clinical outcomes of STEMI patients with a history of CABG or PCI undergoing primary PCI.MethodsWe examined 15,628 STEMI patients who underwent primary PCI at 297 sites in the United States. We used multivariable logistic regression analyses to compare door-to-balloon time delays >90 min and in-hospital major adverse cardiovascular or cerebrovascular events (MACCE).ResultsPatients with previous CABG were significantly older and more likely to have multiple comorbidities (p < 0.0001). Previous CABG was associated with a lower likelihood of a door-to-balloon time ≤90 min compared with patients with no previous revascularization. However, no significant differences in door-to-balloon times were noted between patients with previous PCI and those without previous revascularization. The unadjusted MACCE risk was significantly higher in patients with a history of CABG compared with patients without previous revascularization (odds ratio: 1.68, 95% confidence interval: 1.23 to 2.31). However, after multivariable risk adjustment, there were no significant differences in MACCE risk between the 2 groups. No significant differences in in-hospital outcomes were seen in patients with a previous PCI and those without previous revascularization.ConclusionsIn a large cohort of STEMI patients undergoing primary PCI, patients with previous CABG were more likely to have reperfusion delays, yet risk-adjusted, in-hospital outcomes were similar to those without previous revascularization. No significant differences in reperfusion timeliness and in-hospital outcomes were seen in patients with a history of PCI compared with patients without previous revascularization.     

Safety of Prasugrel Loading Doses in Patients Pre-Loaded With Clopidogrel in the Setting of Primary Percutaneous Coronary Intervention: Results of a Nonrandomized Observational Study

ObjectivesThe aim of this study was to assess the safety of the concurrent administration of a clopidogrel and prasugrel loading dose in patients undergoing primary percutaneous coronary intervention.BackgroundPrasugrel is one of the preferred P2Y₁₂ platelet receptor antagonists for ST-segment elevation myocardial infarction patients. The use of prasugrel was evaluated clinically in clopidogrel-naive patients.MethodsBetween September 2009 and October 2012, a total of 2,023 STEMI patients were enrolled in the COMFORTABLE (Comparison of Biomatrix Versus Gazelle in ST-Elevation Myocardial Infarction [STEMI]) and the SPUM-ACS (Inflammation and Acute Coronary Syndromes) studies. Patients receiving a prasugrel loading dose were divided into 2 groups: 1) clopidogrel and a subsequent prasugrel loading dose; and 2) a prasugrel loading dose. The primary safety endpoint was Bleeding Academic Research Consortium types 3 to 5 bleeding in hospital at 30 days.ResultsOf 2,023 patients undergoing primary percutaneous coronary intervention, 427 (21.1%) received clopidogrel and a subsequent prasugrel loading dose, 447 (22.1%) received a prasugrel loading dose alone, and the remaining received clopidogrel only. At 30 days, the primary safety endpoint was observed in 1.9% of those receiving clopidogrel and a subsequent prasugrel loading dose and 3.4% of those receiving a prasugrel loading dose alone (adjusted hazard ratio [HR]: 0.57; 95% confidence interval [CI]: 0.25 to 1.30, p = 0.18). The HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly) bleeding score tended to be higher in prasugrel-treated patients (p = 0.076). The primary safety endpoint results, however, remained unchanged after adjustment for these differences (clopidogrel and a subsequent prasugrel loading dose vs. prasugrel only; HR: 0.54 [95% CI: 0.23 to 1.27], p = 0.16). No differences in the composite of cardiac death, myocardial infarction, or stroke were observed at 30 days (adjusted HR: 0.66, 95% CI: 0.27 to 1.62, p = 0.36).ConclusionsThis observational, nonrandomized study of ST-segment elevation myocardial infarction patients suggests that the administration of a loading dose of prasugrel in patients pre-treated with a loading dose of clopidogrel is not associated with an excess of major bleeding events. (Comparison of Biomatrix Versus Gazelle in ST-Elevation Myocardial Infarction [STEMI] [COMFORTABLE]; NCT00962416; and Inflammation and Acute Coronary Syndromes [SPUM-ACS]; NCT01000701).     

Procedural Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention: A Report From the NCDR (National Cardiovascular Data Registry)

ObjectivesThe aim of this study was to describe contemporary frequency, predictors, and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in the United States.BackgroundCTO PCI can provide significant clinical benefits, yet there is limited information on its success and safety in unselected patient populations.MethodsWe analyzed the frequency and outcomes of CTO PCI compared with non-CTO PCI in elective patients, and of successful versus failed CTO PCI between July 1, 2009, and March 31, 2013, in the National Cardiovascular Data Registry CathPCI Registry. Generalized estimating equations logistic regression modeling was used to generate independent variables associated with procedural success and procedural complications.ResultsDuring the study period, CTO PCI represented 3.8% of the total PCI volume for stable coronary artery disease (22,365 of 594,510). Overall, patients undergoing CTO PCI required greater contrast volume and longer fluoroscopy time and had lower procedural success (59% vs. 96%, p < 0.001) and higher major adverse cardiac event (1.6% vs. 0.8%, p < 0.001) rates than non-CTO PCI patients. On multivariable analysis, several parameters (including older age, current smoking, previous myocardial infarction, previous coronary artery bypass graft, previous peripheral arterial disease, previous cardiac arrest, right coronary artery CTO target vessel, and less operator experience) were associated with a lower likelihood of CTO PCI procedural success, whereas operators’ annual CTO PCI volume was associated with improved success without a significant increase in major complications.ConclusionsCTO PCI is currently performed infrequently in the United States for stable coronary artery disease and is associated with lower procedural success and higher complication rates compared with non-CTO PCI. Procedural success was associated with several patient factors and operator experience.     

Hybrid Revascularization for Multivessel Coronary Artery Disease

ObjectivesThe aim of this study was to assess the feasibility of hybrid coronary revascularization (HCR) in patients with multivessel coronary artery disease (MVCAD) referred for standard coronary artery bypass grafting (CABG).BackgroundConventional CABG is still the treatment of choice in patients with MVCAD. However, the limitations of standard CABG and the unsatisfactory long-term patency of saphenous grafts are commonly known.MethodsA total of 200 patients with MVCAD involving the left anterior descending artery (LAD) and a critical (>70%) lesion in at least 1 major epicardial vessel (except the LAD) amenable to both PCI and CABG and referred for conventional surgical revascularization were randomly assigned to undergo HCR or CABG (in a 1:1 ratio). The primary endpoint was the evaluation of the safety of HCR. The feasibility was defined by the percent of patients with a complete HCR procedure and the percent of patients with conversions to standard CABG. The occurrence of major adverse cardiac events such as death, myocardial infarction, stroke, repeated revascularization, and major bleeding within the 12-month period after randomization was also assessed.ResultsMost of the pre-procedural characteristics were similar in the 2 groups. Of the patients in the hybrid group, 93.9% had complete HCR and 6.1% patients were converted to standard CABG. At 12 months, the rates of death (2.0% vs. 2.9 %, p = NS), myocardial infarction (6.1% vs. 3.9%, p = NS), major bleeding (2% vs. 2%, p = NS), and repeat revascularization (2% vs. 0%, p = NS) were similar in the 2 groups. In both groups, no cerebrovascular incidents were observed.ConclusionsHCR is feasible in select patients with MVCAD referred for conventional CABG. (Safety and Efficacy Study of Hybrid Revascularization in Multivessel Coronary Artery Disease [POL-MIDES]; NCT01035567).     

Randomized Comparison of FFR-Guided and Angiography-Guided Provisional Stenting of True Coronary Bifurcation Lesions: The DKCRUSH-VI Trial (Double Kissing Crush Versus Provisional Stenting Technique for Treatment of Coronary Bifurcation Lesions VI)

ObjectivesThis study sought to compare the outcomes of fractional flow reserve (FFR)–guided and angiography (Angio)–guided provisional side-branch (SB) stenting for true coronary bifurcation lesions.BackgroundAngio-guided provisional SB stenting after stenting of the main vessel provides favorable outcomes for the majority of coronary bifurcation lesions. Whether an FFR-guided provisional stenting approach is superior has not been studied.MethodsA total of 320 patients with single Medina 1,1,1 and 0,1,1 coronary bifurcation lesions undergoing stenting with a provisional SB approach were randomly assigned 1:1 to Angio-guided and FFR-guided groups. SB stenting was performed for Thrombolysis In Myocardial Infarction flow grade <3, ostial SB stenosis >70%, or greater than type A dissection after main vessel stenting in the Angio-guided group and for SB-FFR <0.80 in the FFR-guided group. The primary endpoint was the 1-year composite rate of major adverse cardiac events (cardiac death, myocardial infarction, and clinically driven target vessel revascularization).ResultsComparing the Angio-guided and FFR-guided groups, treatment of the SB (balloon or stenting) was performed in 63.1% and 56.3% of lesions respectively (p = 0.07); stenting of the SB was attempted in 38.1% and 25.9%, respectively (p = 0.01); and, when attempted, stenting was successful in 83.6% and 73.3% of SBs, respectively (p = 0.01). The 1-year composite major adverse cardiac event rate was 18.1% in both groups (hazard ratio: 0.91, 95% confidence interval: 0.48 to 1.88; p = 1.00). The 1-year target vessel revascularization and stent thrombosis rates were 6.9% and 5.6% (p = 0.82) and 1.3% and 0.6% (p = 0.56) in the Angio-guided and FFR-guided groups, respectively.ConclusionsIn this multicenter, randomized trial, angiographic and FFR guidance of provisional SB stenting of true coronary bifurcation lesions provided similar 1-year clinical outcomes. (Randomized Study on DK Crush Technique Versus Provisional Stenting Technique for Coronary Artery Bifurcation Lesions; ChiCTR-TRC-07000015)     

Radial Versus Femoral Access for Coronary Angiography/Intervention in Women With Acute Coronary Syndromes: Insights From the RIVAL Trial (Radial Vs femorAL access for coronary intervention)

ObjectivesThe purpose of this study was to determine the efficacy and safety of radial versus femoral access in women undergoing coronary angiography/intervention.BackgroundThe risk of bleeding and vascular access site complications are higher in women than in men.MethodsIn a pre-specified RIVAL (RadIal Vs femorAL access for coronary intervention) subgroup analysis, we compared outcomes in women (n = 1,861) and men (n = 5,160) randomized to radial versus femoral access.ResultsOverall, women were at higher risk of major vascular complications compared with men (4.7% vs. 1.7%; p < 0.0001). Major vascular complications were significantly reduced with radial access in women (3.1% vs. 6.1%; hazard ratio [HR]: 0.5; 95% confidence interval [CI]: 0.32 to 0.78; p = 0.002) and in men (0.7% vs. 2.8%; HR: 0.27; 95% CI: 0.17 to 0.45; p < 0.0001; interaction p = 0.092). Crossover rates were higher with radial compared with femoral access in women (11.1% vs. 1.9%; HR: 5.88; p < 0.0001) and men (6.3% vs. 1.9%; HR: 3.32; p < 0.0001; interaction p = 0.054). Percutaneous coronary intervention (PCI) success rates were similar irrespective of access site (women: HR: 1.05; p = 0.471; men: HR: 1.00; p = 0.888; interaction p = 0.674), with no differences in PCI complications. In multivariable analyses, female sex was an independent predictor of major vascular complications (HR: 2.39; 95% CI: 1.76 to 3.25; p < 0.0001). There were consistent findings for women and men, with no difference for the primary composite endpoint of death, myocardial infarction, stroke, and non–coronary artery bypass grafting bleeding (women: 3.9% vs. 5.0%; HR: 0.77; 95% CI: 0.50 to 1.19; men: 3.54% vs. 3.5%; HR: 1.00; 95% CI: 0.75 to −1.34; interaction p = 0.325).ConclusionsWomen undergoing coronary angiography and PCI have a higher risk of vascular access site complications compared with men, and radial access is an effective method to reduce these complications.     

A Combined Optical Coherence Tomography and Intravascular Ultrasound Study on Plaque Rupture,Plaque Erosion,and Calcified Nodule in Patients With ST-Segment Elevation Myocardial Infarction: Incidence,Morphologic Characteristics,and Outcomes After Percutaneous Coronary Intervention

ObjectivesThis study sought to evaluate the incidence of plaque rupture (PR), plaque erosion (PE), and calcified nodule (CN) using optical coherence tomography (OCT) in patients with ST-segment elevation myocardial infarction (STEMI); to compare detailed morphologic plaque characteristics of PR, PE, and CN with optical coherence tomography and intravascular ultrasound; and to compare the post-procedure outcomes among PR, PE, and CN.BackgroundThe incidence and detailed morphologic characteristics of PR, PE, and CN in STEMI patients and their outcome after percutaneous coronary intervention (PCI) are unknown.MethodsA total of 112 STEMI patients who underwent PCI within 12 h from symptom onset were included. Both optical coherence tomography and intravascular ultrasound were performed following aspiration thrombectomy.ResultsThe incidence of PR, PE, and CN was 64.3%, 26.8%, and 8.0%, respectively. PE and CN, compared with PR, had more fibrous plaque (p < 0.001 and p < 0.001) and less thin-cap fibroatheroma (p < 0.001 and p < 0.001) as well as smaller plaque burden (p = 0.003 and p = 0.001) and remodeling index (p = 0.003 and p < 0.001). PE had greater plaque eccentricity index than PR and CN (p < 0.001 and p < 0.001). CN had greater calcified arc and shallower calcium than PR (p < 0.001 and p < 0.001) or PE (p < 0.001 and p < 0.001). More than one-half of CN had negative remodeling. PE had a lower incidence of no-reflow phenomenon after PCI than PR (p = 0.011).ConclusionsPE was the underlying mechanism in one-fourth of STEMI. PE was characterized by eccentric fibrous plaque. CN was characterized by superficial large calcium and negative remodeling. PE was associated with less microvascular damage after PCI.     

Outcomes With Cangrelor Versus Clopidogrel on a Background of Bivalirudin: Insights From the CHAMPION PHOENIX (A Clinical Trial Comparing Cangrelor to Clopidogrel Standard Therapy in Subjects Who Require Percutaneous Coronary Intervention [PCI])

ObjectivesThe aim of this study was to examine the efficacy and bleeding outcomes of cangrelor in patients in the CHAMPION PHOENIX (A Clinical Trial Comparing Cangrelor to Clopidogrel Standard Therapy in Subjects Who Require Percutaneous Coronary Intervention [PCI]) who underwent percutaneous coronary intervention with bivalirudin.BackgroundCangrelor is a potent intravenous P2Y₁₂ inhibitor with rapid onset and offset. In the CHAMPION PHOENIX, cangrelor compared with clopidogrel significantly reduced 48-h ischemic events including stent thrombosis, without increasing major bleeding. Bivalirudin has demonstrated ischemic outcomes similar to those with heparin plus glycoprotein IIb/IIIa inhibition, with reduced bleeding but increased early stent thrombosis.MethodsIn the modified intent-to-treat population, 2,059 patients (18.8%) received bivalirudin, with 1,014 patients in the cangrelor treatment arm and 1,045 in the clopidogrel treatment arm.ResultsAt 48 h, the primary endpoint of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis was lower with cangrelor versus clopidogrel (48 [4.7%] vs. 70 [6.7%]; odds ratio [OR]: 0.68, p = 0.047). Death was similar in both arms (2 [0.2%] vs. 2 [0.2%]). Myocardial infarction was reduced by cangrelor (37 [3.6%] vs. 59 [5.6%]; OR: 0.63, p = 0.03), as was death/myocardial infarction (39 [3.8%] vs. 61 [5.8%]; OR: 0.65, p = 0.04). Cangrelor was associated with a nonsignificant trend toward less stent thrombosis (7 [0.7%] vs. 15 [1.4%]; OR: 0.48, p = 0.10), which was evident within 2 h after percutaneous coronary intervention (p = 0.057). GUSTO (Global Use of Strategies to Open Occluded Arteries) severe bleeding was similar in both arms (2 of 1,021 [0.2%] vs. 2 of 1,055 [0.2%]) as were other bleeding definitions and transfusions. Efficacy and safety results were consistent in patients with stable angina, non–ST-segment elevation acute coronary syndrome, and ST-segment elevation myocardial infarction (p for interaction: 0.62 and 0.29).ConclusionsCangrelor may offer an attractive benefit risk profile when used in combination with bivalirudin.     

Coronary Vessel Wall Contrast Enhancement Imaging as a Potential Direct Marker of Coronary Involvement: Integration of Findings From CAD and SLE Patients

ObjectivesThis study investigated the feasibility of visual and quantitative assessment of coronary vessel wall contrast enhancement (CE) for detection of symptomatic atherosclerotic coronary artery disease (CAD) and subclinical coronary vasculitis in autoimmune inflammatory disease (systemic lupus erythematosus [SLE]), as well as the association with aortic stiffness, an established marker of risk.BackgroundCoronary CE by cardiac magnetic resonance (CMR) is a novel noninvasive approach to visualize gadolinium contrast uptake within the coronary artery vessel wall.MethodsA total of 75 subjects (CAD: n = 25; SLE: n = 27; control: n = 23) underwent CMR imaging using a 3-T clinical scanner. Coronary arteries were visualized by a T2-prepared steady state free precession technique. Coronary wall CE was visualized using inversion-recovery T1 weighted gradient echo sequence 40 min after administration of 0.2 mmol/kg gadobutrol. Proximal coronary segments were visually examined for distribution of CE and quantified for contrast-to-noise ratio (CNR) and total CE area.ResultsCoronary CE was prevalent in patients (93%, n = 42) with a diffuse pattern for SLE and a patchy/regional distribution in CAD patients. Compared with control subjects, CNR values and total CE area in patients with CAD and SLE were significantly higher (mean CNR: 3.9 ± 2.5 vs. 6.9 ± 2.5 vs. 6.8 ± 2.0, respectively; p < 0.001; total CE area: median 0.8 [interquartile range (IQR): 0.6 to 1.2] vs. 3.2 [IQR: 2.6 to 4.0] vs. 3.3 [IQR: 1.9 to 4.5], respectively; p < 0.001). Both measures were positively associated with aortic stiffness (CNR: r = 0.61, p < 0.01; total CE area: 0.36, p = 0.03), hypercholesterolemia (r = 0.68, p < 0.001; r = 0.61, p < 0.001) and hypertension (r = 0.40, p < 0.01; r = 0.32, p < 0.05).ConclusionsWe demonstrate that quantification of coronary CE by CNR and total CE area is feasible for detection of subclinical and clinical uptake of gadolinium within the coronary vessel wall. Coronary vessel wall CE may become an instrumental novel direct marker of vessel wall injury and remodeling in subpopulations at risk.     

Zero-Flow Pressure Measured Immediately After Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction Provides the Best Invasive Index for Predicting the Extent of Myocardial Infarction at 6 Months: An OxAMI Study (Oxford Acute Myocardial Infarction)

ObjectivesThe aim of this study was to define which measure of microvascular best predicts the extent of left ventricular (LV) infarction.BackgroundMicrovascular injury after ST-segment elevation myocardial infarction (STEMI) is an important determinant of outcome. Several invasive measures of the microcirculation at primary percutaneous coronary intervention (PPCI) have been described. One such measure is zero-flow pressure (Pzf), the calculated pressure at which coronary flow would cease.MethodsIn 34 STEMI patients, Pzf, hyperemic microvascular resistance (hMR), and index of microcirculatory resistance (IMR) were derived using thermodilution flow/pressure and Doppler flow/pressure wire assessment of the infarct-related artery following PPCI. The extent of infarction was determined by blinded late gadolinium enhancement on cardiac magnetic resonance at 6 months post-PPCI. Infarction of ≥24% total LV mass was used as a categorical cutoff in receiver-operating characteristic curve analysis.ResultsPzf was superior to both hMR and IMR for predicting ≥24% infarction area under the curve: 0.94 for Pzf versus 0.74 for hMR (p = 0.04) and 0.54 for IMR (p = 0.003). Pzf ≥42 mm Hg was the optimal cutoff value, offering 100% sensitivity and 73% specificity. Patients with Pzf ≥42 mm Hg also had a lower salvage index (61.3 ± 8.1 vs. 44.4 ± 16.8, p = 0.006) and 6-month ejection fraction (62.4 ± 3.6 vs. 49.9 ± 9.6, p = 0.002). In addition, there were significant direct relationships between Pzf and troponin area under the curve (rho = 0.55, p = 0.002), final infarct mass (rho = 0.75, p < 0.0001), percentage of LV infarction and percent transmurality of infarction (rho = 0.77 and 0.74, respectively, p < 0.0001), and inverse relationships with myocardial salvage index (rho = −0.53, p = 0.01) and 6-month ejection fraction (rho = −0.73, p = 0.0001).ConclusionsPzf measured at the time of PPCI is a better predictor of the extent of myocardial infarction than hMR or IMR. Pzf may provide important prognostic information at the time of PPCI and merits further investigation in clinical studies with relevant outcome measures.     

Biochemical Validation of Patient-Reported Symptom Onset Time in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

ObjectivesThis study evaluated a biochemical validation of patient-reported symptom onset time in patients with ST-segment elevation myocardial infarction (STEMI).BackgroundSymptom onset time is an important metric but has never been formally validated.MethodsThe Mayo Clinic Percutaneous Coronary Intervention (PCI) Registry was interrogated to obtain baseline, procedural, and outcome data on 607 STEMI patients undergoing primary PCI. Biochemical onset time was determined by backward extrapolation of serial increasing cardiac troponin T (cTnT) measurements.ResultsThe median patient-reported onset time was 12 min later than the calculated time of first cTnT increase and was therefore estimated to be 4.2 h later than the biochemical onset time (interquartile range: 1.9 to 11.1 h; p < 0.001), assuming a 4-h interval between coronary occlusion and first cTnT increase. Conventional ischemic time showed no association with infarct size (correlation with peak cTnT: r = 0.023; p = 0.61) or 1-year mortality (hazard ratio: 0.97 per doubling; 95% confidence interval: 0.68 to 1.40; p = 0.88). However, after recalculation of ischemic time with biochemical onset time, significant associations with infarct size (r = 0.14; p = 0.001) and 1-year mortality (hazard ratio: 1.70 per doubling; 95% confidence interval: 1.20 to 2.40; p = 0.003) were found. When underestimation of ischemic time by patient-reported onset time increased, so did the risk of mortality.ConclusionsAlthough our point estimate should be interpreted with caution, our study indicates that the actual onset of STEMI is likely to be earlier than the patient-reported onset time. Recalculation of ischemic time with biochemical onset time greatly enhanced its prognostic value. Underestimation of ischemic time by patient-reported onset time occurred more often in high-risk patients.     

Local Low Shear Stress and Endothelial Dysfunction in Patients With Nonobstructive Coronary Atherosclerosis

BackgroundLocal hemodynamic factors are important determinants of atherosclerotic plaque development and progression.ObjectivesThe goal of this study was to determine the association between low endothelial shear stress (ESS) and microvascular and epicardial endothelial dysfunction in patients with early atherosclerosis.MethodsSixty-five patients (mean age 52 ± 11 years) with nonobstructive coronary atherosclerosis (luminal diameter stenosis <30%) were included. Microvascular and epicardial coronary endothelial function was assessed by using intracoronary acetylcholine infusion. Vascular profiling, using 2-plane coronary angiography and intravascular ultrasound, was used to reconstruct the three-dimensional anatomy of the left anterior descending artery. Each reconstructed artery was divided into sequential 3-mm segments and analyzed for local ESS with computational fluid dynamics; that is, lower ESS levels at both a 3-mm regional level (average ESS and low ESS) and at a vessel level (lowest ESS per artery) and for plaque characteristics (plaque area, plaque thickness, and plaque burden).ResultsCoronary segments in arteries with abnormal microvascular function exhibited lower ESS compared with segments in arteries with normal microvascular function (average ESS: 1.67 ± 1.04 Pa vs. 2.03 ± 1.72 Pa [p = 0.050]; lowest ESS: 0.54 ± 0.25 Pa vs. 0.72 ± 0.32 Pa [p = 0.014]). Coronary segments in arteries with abnormal epicardial endothelial function also exhibited significantly lower ESS compared with segments in arteries with normal epicardial function (average ESS: 1.49 ± 0.89 Pa vs. 1.93 ± 1.50 Pa [p < 0.0001]; low ESS: 1.26 ± 0.81 Pa vs. 1.56 ± 1.30 Pa [p = 0.001]; lowest ESS: 0.51 ± 0.27 Pa vs. 0.65 ± 0.29 Pa [p = 0.080]). Patients with abnormal microvascular endothelial function exhibited a progressive decrease in average and low ESS, starting from patients with normal epicardial endothelial function to those with both microvascular and epicardial endothelial dysfunction (p < 0.0001 and p = 0.004, respectively).ConclusionsThese data indicate an association between dysfunction of the microvascular and epicardial endothelium and local ESS at the early stages of coronary atherosclerosis in humans.     

Transradial Versus Transfemoral Access in Patients Undergoing Rescue Percutaneous Coronary Intervention After Fibrinolytic Therapy

ObjectivesThe purpose of this study was to assess usage patterns of transradial access in rescue percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) and associations between vascular access site choice and outcomes.BackgroundTransradial access reduces bleeding and mortality in STEMI patients undergoing primary PCI. Little is known about access site choice and outcomes in patients undergoing rescue PCI after receiving full-dose fibrinolytic therapy for STEMI.MethodsPatients in the National Cardiovascular Data Registry’s CathPCI Registry undergoing rescue PCI for STEMI between 2009 and 2013 were studied. Patients were divided on the basis of access site. Patterns of access use and baseline demographics were noted. Unadjusted and propensity-matched analyses were performed comparing in-hospital bleeding, vascular complications, and mortality outcomes among transradial and transfemoral access patients. The falsification endpoint of gastrointestinal bleeding was specified to assess for persistent unmeasured confounding.ResultsTransradial access was used in 14.2% of cases. In propensity-matched analyses, transradial rescue PCI was associated with significantly less bleeding than transfemoral access (odds ratio [OR]: 0.67; 95% confidence interval [CI]: 0.52 to 0.87; p = 0.003), but not mortality (OR: 0.81; 95% CI: 0.53 to 1.25; p = 0.35). Gastrointestinal bleeding was less frequent in the radial group (OR: 0.23; 95% CI: 0.05 to 0.98; p = 0.05).ConclusionsIn a large, “real-world” registry, transradial access was used in a minority of cases and was associated with significantly less bleeding than transfemoral access in patients undergoing rescue PCI. However, given persistent differences in a falsification endpoint, the influence of treatment-selection bias on these results cannot be ruled out. Further studies are needed to determine predictors of bleeding and mortality in this understudied high-risk group.     

Relation Between Bioresorbable Scaffold Sizing Using QCA-Dmax and Clinical Outcomes at 1 Year in 1,232 Patients From 3 Study Cohorts (ABSORB Cohort B,ABSORB EXTEND,and ABSORB II)

ObjectivesThis study sought to investigate the clinical outcomes based on the assessment of quantitative coronary angiography–maximal lumen diameter (Dmax).BackgroundAssessment of pre-procedural Dmax of proximal and distal sites has been used for Absorb scaffold size selection in the ABSORB studies.MethodsA total of 1,248 patients received Absorb scaffolds in the ABSORB Cohort B (ABSORB Clinical Investigation, Cohort B) study (N = 101), ABSORB EXTEND (ABSORB EXTEND Clinical Investigation) study (N = 812), and ABSORB II (ABSORB II Randomized Controlled Trial) trial (N = 335). The incidence of major adverse cardiac events (MACE) (a composite of cardiac death, any myocardial infarction [MI], and ischemia-driven target lesion revascularization) was analyzed according to the Dmax subclassification of scaffold oversize group versus scaffold nonoversize group.ResultsOf 1,248 patients, pre-procedural Dmax was assessed in 1,232 patients (98.7%). In 649 (52.7%) patients, both proximal and distal Dmax values were smaller than the nominal size of the implanted scaffold (scaffold oversize group), whereas in 583 (47.3%) of patients, the proximal and/or distal Dmax were larger than the implanted scaffold (scaffold nonoversize group). The rates of MACE and MI at 1 year were significantly higher in the scaffold oversize group than in the scaffold nonoversize group (MACE 6.6% vs. 3.3%; log-rank p < 0.01, all MI: 4.6% vs. 2.4%; log-rank p = 0.04), mainly driven by a higher MI rate within 1 month post-procedure (3.5% vs. 1.9%; p = 0.08). The independent MACE determinants were both Dmax smaller than the scaffold nominal size (odds ratio [OR]: 2.13, 95% confidence interval [CI]: 1.22 to 3.70; p < 0.01) and the implantation of overlapping scaffolds (OR: 2.10, 95% CI: 1.17 to 3.80; p = 0.01).ConclusionsImplantation of an oversized Absorb scaffold in a relatively small vessel appears to be associated with a higher 1-year MACE rate driven by more frequent early MI. (ABSORB Clinical Investigation, Cohort B [ABSORB Cohort B], NCT00856856; ABSORB EXTEND Clinical Investigation [ABSORB EXTEND], NCT01023789; ABSORB II Randomized Controlled Trial [ABSORB II], NCT01425281)