Effect of Ischemia Duration and Door-to-Balloon Time on Myocardial Perfusion in ST-Segment Elevation Myocardial Infarction: An Analysis From HORIZONS-AMI Trial (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction)

ObjectivesThis study sought to investigate the effect of treatment delay on microvascular reperfusion in ST-segment elevation myocardial infarction (STEMI) patients from the large, multicenter, prospective HORIZONS-AMI (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction) trial.BackgroundDespite restoration of epicardial blood flow during primary percutaneous coronary intervention (PCI), one-third of patients do not obtain myocardial perfusion due to impairment in the microvascular circulation.MethodsWe examined the effect of symptom onset-to-balloon time (SBT) and door-to-balloon time (DBT) on myocardial reperfusion during primary PCI in STEMI, utilizing resolution of ST-segment elevation (STR) and the myocardial blush grade (MBG). The primary analysis was the relationships between SBT ≤2, >2 to 4, and >4 h and DBT ≤1, >1 to 1.5, >1.5 to 2, and >2 h with MBG and STR. Clinical risk was assessed using a modified version of the Thrombolysis In Myocardial Infarction risk score for STEMI.ResultsIn 2,056 patients, absent microvascular perfusion (MBG 0/1) and STR (STR <30%) after primary PCI was significantly more common in patients with longer SBT, in patients with both low and high clinical risk profiles. By multivariable analysis, SBT (p < 0.0001), anterior infarction (p < 0.0001), reference vessel diameter (p = 0.005), lesion minimum lumen diameter (p < 0.0001), hyperlipidemia (p = 0.03), and current smoking (p = 0.001) were independent predictors of MBG 0/1, whereas SBT (p = 0.007), anterior infarction (p < 0.0001), and history of renal insufficiency (p = 0.0002) were independent predictors of absent STR. DBT (p < 0.0001) was an independent predictor of MBG 0/1. MBG 0/1 and STR<30% identified patients with increased 3-year mortality.ConclusionsThe present study suggests that delay in mechanical reperfusion therapy during STEMI is associated with greater injury to the microcirculation.     

Multimodality Intravascular Imaging to Predict Periprocedural Myocardial Infarction During Percutaneous Coronary Intervention

ObjectivesThe aim of this study is to compare the relative merits of optical coherence tomography (OCT), intravascular ultrasound (IVUS), and near infrared spectroscopy (NIRS) in patients with coronary artery disease for the prediction of periprocedural myocardial infarction (MI).BackgroundAlthough several individual intravascular imaging modalities have been employed to predict periprocedural MI, it is unclear which of the imaging tools would best allow prediction of this complication.MethodsWe retrospectively analyzed 110 patients who underwent OCT, IVUS, and NIRS. Periprocedural MI was defined as a post-procedural cardiac troponin I (cTnI) elevation above 3× the upper limit of normal; analysis was also performed for cTnI ≥5× the upper limit of normal.ResultscTnI ≥3× was observed in 10 patients (9%) and 8 patients had cTnI ≥5×. By OCT, minimum cap thickness was significantly lower (55 vs. 90 μm, p < 0.01), and the plaque burden by IVUS (84 ± 9% vs. 77 ± 8%, p < 0.01) and maximum 4-mm lipid core burden index by NIRS (556 vs. 339, p < 0.01) were greater in the cTnI ≥3× group. Multivariate logistic regression analysis identified cap thickness as the only independent predictor for cTnI ≥3× the upper limit of normal (odds ratio [OR]: 0.90, p = 0.02) or cTnI ≥5× (OR: 0.91, p = 0.04). If OCT findings were excluded from the analysis, plaque burden (OR: 1.13, p = 0.045) and maximum 4-mm lipid core burden index (OR: 1.003, p = 0.037) emerged to be the independent predictors.ConclusionsOCT-based fibrous cap thickness is the most important predictor of periprocedural MI. In the absence of information about cap thickness, NIRS lipid core or IVUS plaque burden best determined the likelihood of the periprocedural event.     

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)     

Outcomes of Comatose Cardiac Arrest Survivors With and Without ST-Segment Elevation Myocardial Infarction: Importance of Coronary Angiography

ObjectivesThe aim of this study was to compare outcomes and coronary angiographic findings in post–cardiac arrest patients with and without ST-segment elevation myocardial infarction (STEMI).BackgroundThe 2013 STEMI guidelines recommend performing immediate angiography in resuscitated patients whose initial electrocardiogram shows STEMI. The optimal approach for those without STEMI post–cardiac arrest is less clear.MethodsA retrospective evaluation of a post–cardiac arrest registry was performed.ResultsThe database consisted of 746 comatose post–cardiac arrest patients including 198 with STEMI (26.5%) and 548 without STEMI (73.5%). Overall survival was greater in those with STEMI compared with those without (55.1% vs. 41.3%; p = 0.001), whereas in all patients who underwent immediate coronary angiography, survival was similar between those with and without STEMI (54.7% vs. 57.9%; p = 0.60). A culprit vessel was more frequently identified in those with STEMI, but also in one-third of patients without STEMI (80.2% vs. 33.2%; p = 0.001). The majority of culprit vessels were occluded (STEMI, 92.7%; no STEMI, 69.2%; p < 0.0001). An occluded culprit vessel was found in 74.3% of STEMI patients and in 22.9% of no STEMI patients. Among cardiac arrest survivors discharged from the hospital who had presented without STEMI, coronary angiography was associated with better functional outcome (93.3% vs. 78.7%; p < 0.003).ConclusionsEarly coronary angiography is associated with improved functional outcome among resuscitated patients with and without STEMI. Resuscitated patients with a presumed cardiac etiology appear to benefit from immediate coronary angiography.     

Impact of Escalating Loading Dose Regimens of Ticagrelor in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention: Results of a Prospective Randomized Pharmacokinetic and Pharmacodynamic Investigation

ObjectivesThe goal of this study was to assess the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of escalating ticagrelor loading dose (LD) regimens in primary percutaneous coronary intervention (PPCI).BackgroundPatients with ST-segment elevation myocardial infarction undergoing PPCI frequently have suboptimal platelet inhibition in the early hours after ticagrelor LD. The use of high ticagrelor LD regimens has been hypothesized to optimize platelet inhibition in PPCI.MethodsThis was a prospective, randomized study of escalating ticagrelor LD regimens (180 mg, 270 mg, or 360 mg) in PPCI (N = 52). PK/PD analyses were performed before and 30 min, 1, 2, 4, 8, and 24 h post-LD. PK assessments included exposure to ticagrelor and its metabolite (AR-C124910XX). PD assessments included P2Y₁₂ reaction units (PRU) measured by VerifyNow P2Y₁₂ and platelet reactivity index (PRI) measured by vasodilator-stimulated phosphoprotein (VASP).ResultsPlatelet reactivity was elevated during the first 2 h post-LD. There were no differences in PRU between groups during the study time course (p = 0.179). There were no significant differences in PRU levels across groups at all time points, except at 1 h (p = 0.017) where platelet reactivity was lowest with a 270-mg LD. No differences were found between the 180-mg and 360-mg groups (primary endpoint; p > 0.999). High on-treatment platelet reactivity rates were not different across groups, except at 1 hour (p = 0.038). Parallel PD findings were observed with VASP-PRI. PK analysis showed a delay in ticagrelor absorption and generation of AR-C124910XX, irrespective of dose. Although morphine was associated with a delay in ticagrelor PK/PD, it was not an independent predictor of high on-treatment platelet reactivity.ConclusionsST-segment elevation myocardial infarction patients undergoing PPCI frequently exhibit impaired response to ticagrelor in the early hours after drug administration, which cannot be overcome by increasing LD regimens. These PD findings are largely attributed to an impaired PK profile, indicating a delay in drug absorption compared with that reported in stable clinical settings. (High Ticagrelor Loading Dose in STEMI; NCT01898442)     

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.     

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.     

Pre-Load Stress Echocardiography for Predicting the Prognosis in Mild Heart Failure

ObjectivesThis study sought to introduce and confirm the efficacy of pre-load stress echocardiography with leg-positive pressure (LPP) for improving risk stratification of patients with mild stable heart failure.BackgroundHeart failure patients with mild symptoms and a poor prognosis should be identified and treated aggressively to improve clinical outcome.MethodsWe performed transthoracic echocardiography with LPP in 202 patients with chronic cardiac disease. Twenty-two of these patients also underwent cardiac catheterization, and left ventricular pressure was measured during LPP along with simultaneous Doppler recordings. Patients were classified into 3 groups on the basis of their left ventricular (LV) diastolic dysfunction as assessed by transmitral flow velocity: restrictive or pseudonormal (PN) at rest, impaired relaxation (IR) at rest and during LPP (stable IR), and IR at rest and PN during LPP (unstable IR). Clinical outcome was compared among these groups.ResultsThe LPP increased LV end-diastolic pressure from 15.8 ± 4.7 mm Hg to 20.5 ± 5.0 mm Hg in the unstable IR group and from 10.5 ± 2.6 mm Hg to 14.7 ± 3.8 mm Hg in the stable IR group (both p < 0.001). During an average follow-up of 548 ± 407 days, 5 patients had cardiac death, 37 had acute heart failure, 4 had an acute myocardial infarction, and 7 had a stroke. The all-cause cardiac event rate in unstable IR was higher than in stable IR (p < 0.001), and was similar in the PN group (p = 0.81). Event-free survival was significantly lower in unstable IR than in stable IR (p = 0.003). In a Cox proportional hazards model, unstable IR was an independent predictor of all-cause cardiac events (hazard ratio: 8.0; p < 0.001).ConclusionsThe left LV end-diastolic pressure-volume relationship can be estimated by changes in transmitral flow velocity during LPP. Thus, pre-load stress echocardiography using LPP provides additional prognostic information in mild heart failure beyond that provided by conventional Doppler echocardiography at rest.     

Impact of Strut Width in Periprocedural Myocardial Infarction: A Propensity-Matched Comparison Between Bioresorbable Scaffolds and the First-Generation Sirolimus-Eluting Stent

ObjectivesThis study aimed to assess the clinical impact of strut width (evaluated by abluminal strut surface area [ASSA]) on periprocedural myocardial infarction (PMI) and clinical outcomes in patients treated with bioresorbable scaffolds (BRS) versus first-generation sirolimus-eluting stents (SES).BackgroundTo date, there are no reports on the impact of ASSA on PMI and clinical outcomes.MethodsWe compared the impact of ASSA on outcomes and PMI in propensity-matched patients treated with BRS and SES. The primary outcome was the incidence of major adverse cardiac events (MACE), defined as the combination of all-cause mortality, follow-up myocardial infarction, and target vessel revascularization, at 30-days and 1-year follow-ups. The secondary endpoint was the incidence of PMI.ResultsAfter propensity-matched analysis, 499 patients (147 BRS patients vs. 352 SES patients) were evaluated. Mean ASSA was higher in patients treated with BRS versus SES (BRS: 132.3 ± 76.7 mm² vs. SES: 67.6 ± 48.4 mm², p < 0.001). MACE was not significantly different between groups (30-days MACE: BRS: 0% vs. SES: 1.4%, p = 0.16, and 1-year MACE: BRS: 15.7% vs. SES: 11.4%, p = 0.67). The incidence of PMI was significantly higher in the BRS group (BRS: 13.1% vs. SES: 7.5%, p = 0.05). Multivariable analyses indicated that treatment of left anterior descending artery and ASSA were independent predictors of PMI.ConclusionsBRS implantation, compared with SES implantation, was associated with a higher incidence of PMI. MACE at 30 days and 1 year were not significantly different. Left anterior descending artery percutaneous coronary intervention and ASSA were independent predictors of PMI.     

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)     

Clinical Outcome of Isolated Tricuspid Regurgitation

ObjectivesThe aim of this study was to assess the outcome of isolated tricuspid regurgitation (TR) and the added value of quantitative evaluation of its severity.BackgroundTR is of uncertain clinical outcome due to confounding comorbidities. Isolated TR (without significant comorbidities, structural valve disease, significant pulmonary artery systolic pressure elevation by Doppler, or overt cardiac cause) is of unknown clinical outcome.MethodsIn patients with isolated TR assessed both qualitatively and quantitatively by a proximal isovelocity surface area method, a long-term outcome analysis was conducted. Patients with severe comorbid diseases were excluded.ResultsThe study involved 353 patients with isolated TR (age 70 years; 33% male; ejection fraction, 63%; all with right ventricular systolic pressure <50 mm Hg). Severe isolated TR was diagnosed in 76 patients (21.5%) qualitatively and 68 patients (19.3%) by quantitative criteria (effective regurgitant orifice [ERO] ≥40 mm²). The 10-year survival and cardiac event rates were 63 ± 5% and 29 ± 5%. Severe isolated TR independently predicted higher mortality (adjusted hazard ratio: 1.78 [95% confidence interval (CI): 1.10 to 2.82], p = 0.02 for qualitative definition and 2.67 [95% CI: 1.66 to 4.23] for an ERO ≥40 mm², p < 0.0001). The addition of grading by quantitative criteria in nested models eliminated the significance of the qualitative grading and improved the model prediction (p < 0.001 for survival and p = 0.02 for cardiac events). The 10-year survival rate was lower with an ERO ≥40 mm² versus <40 mm² (38 ± 7% vs. 70 ± 6%; p < 0.0001), independent of all characteristics, right ventricular size or function, comorbidity, or pulmonary pressure (p < 0.0001 for all), and lower than expected in the general population (p < 0.001). Freedom from cardiac events was lower with an ERO ≥40 mm² versus <40 mm² independently of all characteristics, right ventricular size or function, comorbidity, or pulmonary pressure (p < 0.0001 for all). Cardiac surgery for severe isolated TR was rarely performed (16 ± 5% 5 years after diagnosis).ConclusionsIsolated TR can be severe and is associated with excess mortality and morbidity, warranting heightened attention to diagnosis and quantitation. Quantitative assessment of TR, particularly ERO measurement, is a powerful independent predictor of outcome, superior to standard qualitative assessment.     

Acute Kidney Injury in Patients With Chronic Kidney Disease Undergoing Internal Carotid Artery Stent Implantation

ObjectivesThis study sought to investigate acute kidney injury (AKI) following carotid artery stenting (CAS).BackgroundFew data exist on AKI following CAS.MethodsThis study evaluated 126 chronic kidney disease (CKD) patients who underwent CAS. The risk for contrast-induced AKI was defined by the Mehran score. Hemodynamic depression (i.e., periprocedural systolic blood pressure <90 mm Hg or heart rate <60 beats/min), AKI (i.e., an increase of ≥0.3 mg/dl in the serum creatinine concentration at 48 h), and 30-day major adverse events (including death, stroke, and acute myocardial infarction) were assessed.ResultsAKI occurred in 26 patients (21%). Although baseline kidney function and contrast volume were similar in the AKI group and the non-AKI group, the risk score was higher (10 ± 3 vs. 8 ± 3; p = 0.032), and hemodynamic depression (mostly due to hypotension) (65.5% vs. 35%; p = 0.005) was more common in the AKI group. The threshold of hemodynamic depression duration for AKI development was 2.5 min (sensitivity 54%, specificity 82%). Independent predictors of AKI were hemodynamic depression (odds ratio [OR]: 4.01; 95% confidence interval [CI]: 1.07 to 15.03; p = 0.009), risk score (OR: 1.29; 95% CI: 1.03 to 1.60; p = 0.024), and male sex (OR: 6.07; 95% CI: 1.18 to 31.08; p = 0.021). Independent predictors of 30-day major adverse events that occurred more often in the AKI group (19.5% vs. 7%; p = 0.058) were AKI (HR: 4.83; 95% CI: 1.10 to 21.24; p = 0.037) and hemodynamic depression (HR: 5.58; 95% CI: 1.10 to 28.31; p = 0.038).ConclusionsAKI in CKD patients undergoing CAS is mostly due to hemodynamic depression and is associated with a higher 30-day major adverse events rate.     

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.     

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.     

Persistence of Iatrogenic Atrial Septal Defect After Interventional Mitral Valve Repair With the MitraClip System: A Note of Caution

ObjectivesThe purpose of this study was to investigate the persistence rates of iatrogenic atrial septal defect (iASD) after interventional edge-to-edge repair with serial transesophageal echocardiography examinations and close clinical follow-up (FU).BackgroundTranscatheter mitral valve repair (TMVR) with the MitraClip system (Abbott Vascular, Abbott Park, Illinois) is a therapeutic alternative to surgery in selected high-risk patients. Clip placement requires interatrial transseptal puncture and meticulous manipulation of the steerable sheath. The persistence of iASD after MitraClip procedures and its clinical relevance is unknown.MethodsA total of 66 patients (76.7% male, mean age 77.1 ± 7.9 years) with symptomatic mitral regurgitation (MR) at prohibitive surgical risk (EuroSCORE II 10.1 ± 6.1%) underwent MitraClip procedures and completed 6 months of FU.ResultsTransesophageal echocardiography after FU showed persistent iASD in 50% of cases. Patients with iASD did not significantly differ from patients without ASD concerning baseline characteristics, New York Heart Association functional class, severity of MR, and acute procedural success rates (p > 0.05). When comparing procedural details and hemodynamic measures between groups, MitraClip procedures took longer in patients without iASD (82.4 ± 39.7 min vs. 68.9 ± 45.5 min; p = 0.05), and echocardiography after FU showed less decrease of systolic pulmonary artery pressures in the iASD group (−1.6 ± 14.1 mm Hg vs. 9.3 ± 17.4 mm Hg; p = 0.02). Clinically, patients with iASD presented more often with New York Heart Association functional classes >II after FU (57% vs. 30%; p = 0.04), showed higher levels of N-terminal pro-brain natriuretic peptide (6,667.3 ± 7,363.9 ng/dl vs. 4,835.9 ± 6,681.7 ng/dl; p = 0.05), and had less improvement in 6-min walking distances (20.8 ± 107.4 m vs. 114.6 ± 116.4 m; p = 0.001). Patients with iASD showed higher death rates during 6 months (16.6% vs. 3.3%; p = 0.05). Cox regression analysis found that only persistence of iASD (p = 0.04) was associated with 6-month survival.ConclusionsThe persistence rate of 50% iASD after MitraClip procedures is considerably high. Persistent interatrial shunting was associated with worse clinical outcomes and increased mortality. Further studies are warranted to investigate if persistent interatrial shunting is the mediator or marker of advanced disease in these patients.     

Coronary Artery Calcification and Family History of Myocardial Infarction in the Dallas Heart Study

ObjectivesThis study aimed to investigate the independent and joint associations between family history of myocardial infarction (FH) and coronary artery calcification (CAC) with incident coronary heart disease (CHD).BackgroundFH and CAC are associated with each other and with incident CHD. It is not known whether FH retains its predictive value after CAC results are accounted for.MethodsAmong 2,390 participants without cardiovascular disease enrolled in the Dallas Heart Study, we assessed FH (myocardial infarction in a first-degree relative) and prevalent CAC by electron-beam computed tomography. The primary outcome, a composite of CHD-related death, myocardial infarction, and percutaneous or surgical coronary revascularization, was assessed over a mean follow-up of 8.0 ± 1.2 years. The individual and joint associations with the CHD composite outcome were determined for FH and CAC.ResultsThe mean age of the population was 44 ± 9 years; 32% had FH and 47% had a CAC score of 0. In multivariate models adjusted for traditional risk factors, FH was independently associated with CHD (adjusted hazard ratio: 2.6; 95% confidence interval: 1.6 to 4.2; p < 0.001). Further adjustment for prevalent CAC did not diminish this association (adjusted hazard ratio: 2.6; 95% confidence interval: 1.6 to 4.2; p < 0.001). FH and CAC were additive: CHD event rates in those with both FH and CAC were 8.8% vs. 3.3% in those with prevalent CAC alone (p < 0.001). CHD rates were 1.9% in those with FH alone compared with 0.4% in those with neither FH nor CAC (p < 0.017). Among subjects without CAC, FH characterized a group with a more unfavorable cardiometabolic profile.ConclusionsFH provided prognostic information that was independent of and additive to CAC. Among those with CAC, FH identified subjects at particularly high short-term risk, and, among those without it, selected a group with an adverse risk-factor profile.     

A Prospective,Single-Arm,Multicenter Trial of Ultrasound-Facilitated,Catheter-Directed,Low-Dose Fibrinolysis for Acute Massive and Submassive Pulmonary Embolism: The SEATTLE II Study

ObjectivesThis study conducted a prospective, single-arm, multicenter trial to evaluate the safety and efficacy of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis, using the EkoSonic Endovascular System (EKOS, Bothell, Washington).BackgroundSystemic fibrinolysis for acute pulmonary embolism (PE) reduces cardiovascular collapse but causes hemorrhagic stroke at a rate exceeding 2%.MethodsEligible patients had a proximal PE and a right ventricular (RV)-to-left ventricular (LV) diameter ratio ≥0.9 on chest computed tomography (CT). We included 150 patients with acute massive (n = 31) or submassive (n = 119) PE. We used 24 mg of tissue-plasminogen activator (t-PA) administered either as 1 mg/h for 24 h with a unilateral catheter or 1 mg/h/catheter for 12 h with bilateral catheters. The primary safety outcome was major bleeding within 72 h of procedure initiation. The primary efficacy outcome was the change in the chest CT–measured RV/LV diameter ratio within 48 h of procedure initiation.ResultsMean RV/LV diameter ratio decreased from baseline to 48 h post-procedure (1.55 vs. 1.13; mean difference, −0.42; p < 0.0001). Mean pulmonary artery systolic pressure (51.4 mm Hg vs. 36.9 mm Hg; p < 0.0001) and modified Miller Index score (22.5 vs. 15.8; p < 0.0001) also decreased post-procedure. One GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries)–defined severe bleed (groin hematoma with transient hypotension) and 16 GUSTO-defined moderate bleeding events occurred in 15 patients (10%). No patient experienced intracranial hemorrhage.ConclusionsUltrasound-facilitated, catheter-directed, low-dose fibrinolysis decreased RV dilation, reduced pulmonary hypertension, decreased anatomic thrombus burden, and minimized intracranial hemorrhage in patients with acute massive and submassive PE. (A Prospective, Single-arm, Multi-center Trial of EkoSonic® Endovascular System and Activase for Treatment of Acute Pulmonary Embolism (PE) [SEATTLE II]; NCT01513759)     

Real-Time Ultrasound Guidance Facilitates Transradial Access: RAUST (Radial Artery Access With Ultrasound Trial)

ObjectivesThis study sought to assess the utility of ultrasound (US) guidance for transradial arterial access.BackgroundUS guidance has been demonstrated to facilitate vascular access, but has not been tested in a multicenter randomized fashion for transradial cardiac catheterization.MethodsWe conducted a prospective multicenter randomized controlled trial of 698 patients undergoing transradial cardiac catheterization. Patients were randomized to needle insertion with either palpation or real-time US guidance (351 palpation, 347 US). Primary endpoints were the number of forward attempts required for access, first-pass success rate, and time to access.ResultsThe number of attempts was reduced with US guidance [mean: 1.65 ± 1.2 vs. 3.05 ± 3.4, p < 0.0001; median: 1 (interquartile range [IQR]: 1 to 2) vs. 2 (1 to 3), p < 0.0001] and the first-pass success rate improved (64.8% vs. 43.9%, p < 0.0001). The time to access was reduced (88 ± 78 s vs. 108 ± 112 s, p = 0.006; median: 64 [IQR: 45 to 94] s vs. 74 [IQR: 49 to 120] s, p = 0.01). Ten patients in the control group required crossover to US guidance after 5 min of failed palpation attempts with 8 of 10 (80%) having successful sheath insertion with US. The number of difficult access procedures was decreased with US guidance (2.4% vs. 18.6% for ≥5 attempts, p < 0.001; 3.7% vs. 6.8% for ≥5min, p = 0.07). No significant differences were observed in the rate of operator-reported spasm, patient pain scores following the procedure, or bleeding complications.ConclusionsUltrasound guidance improves the success and efficiency of radial artery cannulation in patients presenting for transradial catheterization. (Radial Artery Access With Ultrasound Trial [RAUST]; NCT01605292)     

CMR-Verified Diffuse Myocardial Fibrosis Is Associated With Diastolic Dysfunction in HFpEF

ObjectivesThe purpose of this study was to investigate diffuse myocardial fibrosis in patients with systolic heart failure (SHF) and in patients with heart failure with preserved ejection fraction (HFpEF) and the association with diastolic dysfunction of the left ventricle (LV).BackgroundIncreased diffuse myocardial fibrosis may impair LV diastolic function. However, no study has verified the association between the degree of diffuse myocardial fibrosis and the severity of impaired diastolic function in SHF and HFpEF.MethodsForty patients with SHF, 62 patients with HFpEF, and 22 patients without HF underwent cardiac magnetic resonance (CMR), including T1 mapping and cine CMR on a 3-T system. Extracellular volume fraction (ECV), a measure of diffuse myocardial fibrosis, was quantified from T1 mapping. Systolic and diastolic functions of the LV were assessed by cine CMR. The ECV values and LV functional indexes were compared among the 3 groups. Associations between ECV and LV diastolic function were also investigated.ResultsCompared with patients without HF, significantly higher ECV was found in patients with SHF (31.2% [interquartile range (IQR): 29.0% to 34.1%] vs. 27.9% [IQR: 26.2% to 29.4%], p < 0.001) and HFpEF (28.9% [IQR: 27.8% to 31.3%] vs. 27.9% [IQR: 26.2% to 29.4%], p = 0.006). Peak filling rate, a diastolic functional index assessed by cine CMR, was significantly decreased in patients with SHF (1.00 s⁻¹ [IQR: 0.79 to 1.49 s⁻¹] vs. 3.86 s⁻¹ [IQR: 3.34 to 4.48 s⁻¹], p < 0.001) and HFpEF (2.89 s⁻¹ [IQR: 2.13 to 3.50 s⁻¹] vs. 3.86 s⁻¹ [IQR: 3.34 to 4.48 s⁻¹], p < 0.001). Myocardial ECV was significantly correlated with peak filling rate in the HFpEF group (r = −0.385, p = 0.002), but no correlation was found in the SHF and non-HF groups (r = 0.030, p = 0.856 and r = −0.238, p = 0.285, respectively).ConclusionsIn patients with HF, only those with HFpEF show a significant correlation between increased diffuse myocardial fibrosis and impaired diastolic function. Diffuse myocardial fibrosis plays a unique role in the pathogenesis of HFpEF.     

Atrial Remodeling Following Catheter-Based Renal Denervation Occurs in a Blood Pressure– and Heart Rate–Independent Manner

ObjectivesThis study sought to investigate left atrial (LA) remodeling in relation to blood pressure (BP) and heart rate (HR) after renal sympathetic denervation (RDN).BackgroundIn addition to reducing BP and HR in certain patients with hypertension, RDN can decrease left ventricular (LV) mass and ameliorate LV diastolic dysfunction.MethodsBefore and 6 months after RDN, BP, HR, LV mass, left atrial volume index (LAVI), diastolic function (echocardiography), and premature atrial contractions (PAC) (Holter electrocardiogram) were assessed in 66 patients with resistant hypertension.ResultsRDN reduced office BP by 21.6 ± 3.0/10.1 ± 2.0 mm Hg (p < 0.001), and HR by 8.0 ± 1.3 beats/min (p < 0.001). At baseline, LA size correlated with LV mass, diastolic function, and pro-brain natriuretic peptide, but not with BP or HR. Six months after RDN, LAVI was reduced by 4.0 ± 0.7 ml/kg/m² (p < 0.001). LA size decrease was stronger when LAVI at baseline was higher. In contrast, the decrease in LAVI was not dependent on LV mass or diastolic function (E/E′ or E/A) at baseline. Furthermore, LAVI decreased without relation to decrease in systolic BP or HR. Additionally, occurrence of PAC (median of >153 PAC/24 h) was reduced (to 68 PAC/24 h) by RDN, independently of changes in LA size.ConclusionsIn patients with resistant hypertension, LA volume and occurrence of PAC decreased 6 months after RDN. This decrease was independent of BP and HR at baseline or the reduction in BP and HR reached by renal denervation. These data suggest that there is a direct, partly BP-independent effect of RDN on cardiac remodeling and occurrence of premature atrial contractions.