Noninvasive Discrimination of Coronary Chronic Total Occlusion and Subtotal Occlusion by Coronary Computed Tomography Angiography

ObjectivesThe aim of this study was to investigate whether noninvasive discrimination of chronic total occlusion (CTO), a complete interruption of coronary artery flow, and subtotal occlusion (STO), a functional total occlusion, is feasible using coronary computed tomography angiography (CTA).BackgroundCTO and STO may be different in pathophysiology and clinical treatment strategy.MethodsWe included 486 consecutive patients (median age 63 years, 82% male) who showed a total of 553 completely occluded coronary arteries in coronary CTA. The length of occlusion, side branches, shape of proximal stump, and collateral vessels were measured as anatomical findings. Transluminal attenuation gradient, which reflects intraluminal contrast kinetics and functional extent of collateral flow, was measured as a physiological surrogate. All patients were followed by invasive coronary angiography.ResultsCoronary arteries with CTO showed longer occlusion length (cutoff ≥15 mm), higher distal transluminal attenuation gradient (cutoff ≥−0.9 Hounsfield units [HU]/10 mm), more frequent side branches, blunted stump, cross-sectional calcification ≥50%, and collateral vessels compared with arteries with STO (p < 0.001, all). The combination of these findings could distinguish CTO from STO (c-statistics = 0.88 [95% confidence interval: 0.94 to 0.90], sensitivity 83%, specificity 77%, positive predictive value 55%, negative predictive value 93%; p < 0.001). Percutaneous coronary intervention (PCI) was attempted in 342 arteries and was successful in 279 arteries (82%). The computed tomography findings could predict the unsuccessful PCI (c-statistics = 0.70 [95% confidence interval: 0.65 to 0.75], sensitivity 63%, specificity 73%, positive predictive value 91%, negative predictive value 31%; p < 0.001).ConclusionsNoninvasive coronary CTA could discern CTO from STO, and also could predict the success of attempted PCI.     

Outcomes After Emergency Percutaneous Coronary Intervention in Patients With Unprotected Left Main Stem Occlusion: The BCIS National Audit of Percutaneous Coronary Intervention 6-Year Experience

ObjectivesThis study sought to evaluate in-hospital outcomes and 3-year mortality of patients presenting with unprotected left main stem occlusion (ULMSO) treated with primary percutaneous coronary intervention (PPCI).BackgroundLimited data exists about management and outcome following presentation with ULMSO.MethodsFrom January 1, 2007 to December 21, 2012, 446,257 PCI cases were recorded in the British Cardiovascular Intervention Society database of all PCI cases in England and Wales. Of those, 568 were patients having emergency PCI for ST-segment elevation infarction (0.6% of all PPCI) who presented with ULMSO (TIMI [Thrombolysis In Myocardial Infarction] flow grade 0/1 and stenosis >75%), and they were compared with 1,045 emergency patients treated with nonocclusive LMS disease. Follow-up was obtained through linkage with the Office of National Statistics.ResultsPresentation with ULMSO, compared with nonocclusive LMS disease, was associated with a doubling in the likelihood of periprocedural shock (57.9% vs. 27.9%; p < 0.001) and/or intra-aortic balloon pump support (52.5% vs. 27.2%; p < 0.001). In-hospital (43.3% vs. 20.6%; p < 0.001), 1-year (52.8% vs. 32.4%; p < 0.001), and 3-year mortality (73.9% vs 52.3%, p < 0.001) rates were higher in patients with ULMSO, compared with patients presenting with a patent LMS, and were significantly influenced by the presence of cardiogenic shock. ULMSO and cardiogenic shock were independent predictors of 30-day (hazard ratio [HR]: 1.61 [95% confidence interval (CI): 1.07 to 2.41], p = 0.02, and HR: 5.43 [95% CI: 3.23 to 9.12], p<0.001, respectively) and 3-year all-cause mortality (HR: 1.52 [95% CI: 1.06 to 2.17], p = 0.02, and HR: 2.98 [95% CI: 1.99 to 4.49], p < 0.001, respectively).ConclusionsIn patients undergoing PPCI for ULMSO, acute outcomes are poor and additional therapies are required to improve outcome. However, long-term outcomes for survivors of ULMSO are encouraging.     

Long-Term Survival Benefit of Revascularization Compared With Medical Therapy in Patients With Coronary Chronic Total Occlusion and Well-Developed Collateral Circulation

ObjectivesThe purpose of this study was to compare the long-term clinical outcomes of patients with chronic total occlusion (CTO) and well-developed collateral circulation treated with revascularization versus medical therapy.BackgroundLittle is known about the clinical outcomes and optimal treatment strategies of CTO with well-developed collateral circulation.MethodsWe screened 2,024 consecutive patients with at least 1 CTO detected on coronary angiogram. Of these, we analyzed data from 738 patients with Rentrop 3 grade collateral circulation who were treated with medical therapy alone (n = 236), coronary artery bypass grafting (n = 170) or percutaneous coronary intervention (n = 332; 80.1% successful). Patients who underwent revascularization and medical therapy (revascularization group, n = 502) were compared with those who underwent medical therapy alone (medication group, n = 236) in terms of cardiac death and major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction, and repeat revascularization.ResultsDuring a median follow-up duration of 42 months, multivariate analysis revealed a significantly lower incidence of cardiac death (hazard ratio [HR]: 0.29; 95% confidence interval [CI]: 0.15 to 0.58; p < 0.01) and MACE (HR: 0.32; 95% CI: 0.21 to 0.49; p < 0.01) in the revascularization group compared with the medication group. After propensity score matching, the incidence of cardiac death (HR: 0.27; 95% CI: 0.09 to 0.80; p = 0.02) and MACE (HR: 0.44; 95% CI: 0.23 to 0.82; p = 0.01) were still significantly lower in the revascularization group than in the medication group.ConclusionsIn patients with coronary CTO and well-developed collateral circulation, aggressive revascularization may reduce the risk of cardiac mortality and MACE.     

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.     

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.     

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.     

Percutaneous Circulatory Assist Devices for High-Risk Coronary Intervention

A unifying definition of what constitutes high-risk percutaneous coronary intervention remains elusive. This reflects the existence of several recognized patient, anatomic, and procedural characteristics that, when combined, can contribute to elevating risk. The relative inability to withstand the adverse hemodynamic sequelae of dysrhythmia, transient episodes of ischemia-reperfusion injury, or distal embolization of atherogenic material associated with coronary intervention serve as a common thread to tie this patient cohort together. This enhanced susceptibility to catastrophic hemodynamic collapse has triggered the development of percutaneous cardiac assist devices such as the intra-aortic balloon pump, Impella (Abiomed Inc., Danvers, Massachusetts), TandemHeart (CardiacAssist, Inc., Pittsburgh, Pennsylvania), and extracorporeal membranous oxygenation to provide adjunctive mechanical circulatory support. In this state-of-the-art review, we discuss the physiology underpinning their application. Thereafter, we examine the results of several randomized multicenter trials investigating their use in high-risk coronary intervention to determine which patients would benefit most from their implantation and whether there is a signal to delineate whether they should be used in an elective pre-procedure, standby, rescue, or routine post-procedure fashion.     

Coronary Computed Tomographic Prediction Rule for Time-Efficient Guidewire Crossing Through Chronic Total Occlusion: Insights From the CT-RECTOR Multicenter Registry (Computed Tomography Registry of Chronic Total Occlusion Revascularization)

ObjectivesThis study sought to establish a coronary computed tomography angiography prediction rule for grading chronic total occlusion (CTO) difficulty for percutaneous coronary intervention (PCI).BackgroundThe uncertainty of procedural outcome remains the strongest barrier to PCI in CTO.MethodsData from 4 centers involving 240 consecutive CTO lesions with pre-procedural coronary computed tomography angiography were analyzed. Successful guidewire (GW) crossing ≤30 min was set as an endpoint to eliminate operator bias. The CT-RECTOR (Computed Tomography Registry of Chronic Total Occlusion Revascularization) score was developed by assigning 1 point for each independent predictor, and then summing all points accrued. Continuous distribution of scores was used to stratify CTO into 4 difficulty groups: easy (score 0); intermediate (score 1); difficult (score 2); and very difficult (score ≥3). Discriminatory performance was tested by 10-fold cross-validation and compared with the angiographic J-CTO (Multicenter CTO Registry of Japan) score.ResultsStudy endpoint was achieved in 55% of cases. Multivariable analysis yielded multiple occlusions, blunt stump, severe calcification, bending, duration of CTO ≥12 months, and previously failed PCI as independent predictors for GW crossing. The probability of successful GW crossing ≤30 min for each group (from easy to very difficult) was 95%, 88%, 57%, and 22%, respectively. Areas under receiver-operator characteristic curves for the CT-RECTOR and J-CTO scores were 0.83 and 0.71, respectively (p < 0.001). Both the original model fit and 10-fold cross-validation correctly classified 77.3% of lesions.ConclusionsThe CT-RECTOR score represents a simple and accurate noninvasive tool for predicting time-efficient GW crossing that may aid in grading CTO difficulty before PCI. (Computed Tomography Angiography Prediction Score for Percutaneous Revascularization for Chronic Total Occlusions [CT-RECTOR]; NCT02022878)     

Validation and Comparison of the Long-Term Prognostic Capability of the SYNTAX Score-II Among 1,528 Consecutive Patients Who Underwent Left Main Percutaneous Coronary Intervention

ObjectivesThis study sought to evaluate the long-term prognostic capacity of the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score II (SS-II) and compare it with other risk scores among patients undergoing left main percutaneous coronary intervention (LM-PCI).BackgroundRecently, the SS-II was developed in an attempt to individualize and help the decision-making process between PCI and coronary artery bypass graft (CABG) surgery in the management of complex coronary artery disease (CAD). However, there is a paucity of data regarding the utility of SS-II in patients undergoing LM-PCI.MethodsData from 1,528 consecutive patients from a single center undergoing unprotected LM-PCI were prospectively collected. The SS-II and other scores were then derived using patients’ baseline clinical characteristics. Patients were stratified according to tertiles of SS-II for PCI: SS-II ≤21 (n = 508), SS-II >21 and ≤28 (n = 480), and >28 (n = 540). Predictive capability for long-term mortality was compared between angiographic scores and scores combining both angiographic and clinical variables.ResultsAt a mean follow-up of 4.4 years, mortality in the first, second, and third SS-II tertiles was 1.8%, 3.5%, and 9.4%, respectively (p < 0.0001). Multivariate analysis showed SS-II to be a strong independent predictor of mortality (hazard ratio: 1.76, 95% confidence interval: 1.10 to 2.82; p = 0.02) after LM-PCI. When compared with the angiographic SS, scores combining both clinical and angiographic variables, such as the SS-II, were superior in terms of long-term prognostication.ConclusionsResults of this large series of consecutive patients who underwent unprotected LM-PCI suggested that the SS-II has better long-term prognostic power in terms of mortality compared with the original purely angiographic SS.     

Outcomes in Patients With Cardiogenic Shock Following Percutaneous Coronary Intervention in the Contemporary Era: An Analysis From the BCIS Database (British Cardiovascular Intervention Society)

ObjectivesThis study sought to determine mortality rates among cardiogenic shock (CGS) patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome in the contemporary treatment era and to determine predictors of mortality.BackgroundIt is unclear whether recent advances in pharmacological and interventional strategies have resulted in further improvements in short- and long-term mortality and which factors are associated with adverse outcomes in patients presenting with CGS and undergoing PCI in the setting of acute coronary syndrome.MethodsThis study analyzed prospectively collected data for patients undergoing PCI in the setting of CGS as recorded in the BCIS (British Cardiovascular Intervention Society) PCI database.ResultsIn England and Wales, 6,489 patients underwent PCI for acute coronary syndrome in the setting of CGS. The mortality rates at 30 days, 90 days, and 1 year were 37.3%, 40.0%, and 44.3%, respectively. On multiple logistic regression analysis, age (for each 10-year increment of age: odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.51 to 1.68; p < 0.0001), diabetes mellitus (OR: 1.47, 95% CI: 1.28 to 1.70; p < 0.0001), history of renal disease (OR: 2.03, 95% CI: 1.63 to 2.53; p < 0.0001), need for artificial mechanical ventilation (OR: 2.56, 95% CI: 2.23 to 2.94; p < 0.0001), intra-aortic balloon pump use (OR: 1.57, 95% CI: 1.40 to 1.76; p < 0.0001), and need for left main stem PCI (OR: 1.90, 95% CI: 1.62 to 2.23; p < 0.0001) were associated with higher mortality at 1 year.ConclusionsIn this large U.K. cohort of patients undergoing PCI in the context of CGS, mortality remains high in spite of the use of contemporary PCI strategies. The highest mortality occurs early, and this time period may be a particular target of therapeutic intervention.     

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.     

Safety and Effectiveness of Everolimus-Eluting Stents in Chronic Total Coronary Occlusion Revascularization: Results From the EXPERT CTO Multicenter Trial (Evaluation of the XIENCE Coronary Stent,Performance, and Technique in Chronic Total Occlusions)

ObjectivesThis study sought to evaluate procedural and clinical outcomes among patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI) using contemporary methods and everolimus-eluting stents (EES).BackgroundLimited studies have detailed the procedural and late-term safety and efficacy of CTO revascularization among multiple centers applying modern techniques and with newer-generation drug-eluting stents.MethodsAmong 20 centers, 250 consecutive patients were enrolled for attempted CTO PCI. Procedural and in-hospital clinical outcomes were examined in addition to the 1-year primary endpoint of death, myocardial infarction, and target lesion revascularization (major adverse cardiac events [MACE]).ResultsDemographic, lesion, and procedural characteristics included prior bypass surgery: 9.9%; diabetes: 40.1%; lesion length: 36.1 ± 18.5 mm; and stent length: 51.7 ± 27.2 mm. Procedural success, defined as guidewire recanalization with no in-hospital MACE, was 96.4%. Success with antegrade-only methods was 97.9% and 86.2% by retrograde/combined methods, respectively. Compared with a pre-specified performance goal derived from 6 prior CTO drug-eluting stent trials (1-year MACE: 24.4%), treatment with EES was associated with significantly lower composite adverse events for both intent-to-treat (18.5%, 1-sided upper confidence interval: 23.4%, p = 0.025) and per-protocol populations (8.2%, 1-sided upper confidence interval: 12.3%, p < 0.0001). Target lesion revascularization at 1 year was 6.3%. Dual antiplatelet therapy adherence was 53.9% at 1 year, yet subacute definite stent thrombosis occurred in only 2 patients (0.9%), and late probable stent thrombosis occurred in 1 patient (0.5%).ConclusionsIn a multicenter registration trial representing contemporary technique and EES, favorable procedural success and late-term clinical outcomes support CTO PCI in a patient population with high lesion complexity. (EXPERT CTO: Evaluation of the XIENCE PRIME LL and XIENCE Nano Everolimus Eluting Coronary Stent Coronary Stents, Performance, and Technique in Chronic Total Occlusions; NCT01435031)