The Role of Index of Microcirculatory Resistance in Left Anterior Descending Artery ST Segment Elevation Myocardial Infarction Patients after Primary Percutaneous Coronary Intervention.

Background: Our aim was to assess the relationship of the index of microvascular resistance (IMR) in left anterior descending (LAD) artery involved STEMI patients. Methods: Data of 316 STEMI patients who had undergone primary percutaneous coronary intervention (PCI) were collected from three cardiovascular centers from 2005 to 2015. In total, 246 patients with LAD STEMI were enrolled for IMR evaluation. Patients were divided into two groups respective of the cut-off IMR value of 30. All-cause mortality, left ventricular function, improvement of systolic function, and cardiac biomarkers were analyzed and compared. Results: A total of 246 patients were enrolled. The number of patients in the IMR above 30 group was 93 and below 30 was 153. The mean ages for each group were 57.91 ± 11.99 and 54 ± 10.63, respectively. The peak creatinine kinase (CK) (3936.85 ± 2827.32 IU/L vs. 2218.08 ± 2310.41 IU/L, p < 0.001) and CKmb (336.15 ± 195.08 mg/mL vs. 231.53 ± 179.53 mg/mL, p < 0.001) levels were higher for an IMR above the 30 group. The left ventricular ejection fraction (LVEF) (44.57 ± 6.685% vs. 47.35 ± 8.17%, p = 0.006) and improvement of LVEF (2.81 ± 7.135% vs. 5.88 ± 7.65%, p = 0.004) was lower in the IMR above 30 group. All-cause mortality (7.5% vs. 1.3%, p = 0.012) was higher in the IMR above 30 group, and a Cox regression analysis showed that an IMR above 30 was a poor prognostic factor regarding all-cause mortality (HR: 5.151, 95% CI 1.062-24.987, p = 0.042) even after adjusting for classical clinical risk factors. Conclusions: An elevated IMR value represented larger infarct size, more severe LV dysfunction, and higher mortality in LAD STEMI patients after successful PCI.

Seasonal variation and prognosis in patients with acute myocardial infarction complicated by cardiogenic shock.

Background: Little is known about the association between seasonal variation and prognosis in patients with CS caused by AMI. Objectives: We investigated the 12-month clinical outcomes in patients treated with percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) according to season. Methods: A total of 695 patients undergoing PCI for AMI complicated by CS was enrolled from 12 centers in South Korea. The study patients were divided into four groups according to season in which the AMI with CS occurred (spring, n = 178 vs. summer, n = 155 vs. autumn, n = 182 vs. winter, n = 180). We compared major adverse cardiovascular events (MACEs; the composite of cardiac death, myocardial infarction, re-hospitalization due to heart failure, and any revascularization) between the four groups. Results: The risk of MACE during the 12 months after CS was similar in the four groups: spring, 68 patients, vs. summer, 69, vs. autumn, 73, vs. winter, 68 (p = 0.587). Multivariate Cox-regression analysis revealed no significant difference in 12-month MACE among groups compared to the spring group after inverse probability of treatment weighting adjustment (summer, HR 1.40, 95 % CI 0.98-1.99, p = 0.062; autumn, HR 1.26, 95 % CI 0.89-1.80, p = 0.193; winter, HR 1.18, 95 % CI 0.83-1.67, p = 0.356). The similarity of MACE between the four groups was consistent across a variety of subgroups. Conclusions: After adjusting for baseline differences, seasonal variation seems not to influence the mid-term risk of 12-month MACE in patients treated with PCI for AMI complicated by CS. Condensed abstract: Data are limited regarding the association between seasonal variation and prognosis in patients with cardiogenic shock (CS) caused by AMI. This study divided patients undergoing PCI for AMI complicated by CS into four groups based on the season of occurrence and found no significant differences in 12-month MACE between the groups after adjusting for bias and confounding factors. Multivariate analysis revealed consistent MACE similarity across subgroups. The study suggests that seasonal variation has no impact on the mid-term risk of 12-month MACE in patients with CS caused by AMI, after adjusting for baseline differences. Trial registration: ClinicalTrials.gov NCT02985008RESCUE (REtrospective and prospective observational Study to investigate Clinical oUtcomes and Efficacy of left ventricular assist device for Korean patients with cardiogenic shock), NCT02985008, Registered December 5, 2016 - retrospectively and prospectively. Irb information: This study was approved by the institutional review board of Samsung Medical Center (Reference number: 2016-03-130).

Efficacy and safety of durable versus biodegradable polymer drug-eluting stents in patients with acute myocardial infarction complicated by cardiogenic shock.

The clinical impact of different polymer technologies in newer-generation drug-eluting stents (DESs) for patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) remains poorly understood. We investigated the efficacy and safety of durable polymer DESs (DP-DESs) compared with biodegradable polymer DESs (BP-DESs). A total of 620 patients who underwent percutaneous coronary intervention with newer-generation DESs for AMI complicated by CS was divided into two groups based on polymer technology: the DP-DES group (n = 374) and the BP-DES group (n = 246). The primary outcome was target vessel failure (TVF) during a 12-month follow-up, defined as a composite of cardiac death, myocardial infarction, or target vessel revascularization. Both the DP-DES and BP-DES groups exhibited low stent thrombosis rates (1.3% vs. 1.6%, p = 0.660). The risk of TVF did not significantly differ between the two groups (34.2% vs. 28.5%, hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.69-1.29, p = 0.721). This finding remained consistent after adjustment with inverse probability of treatment weighting (28.1% vs. 25.1%, HR 0.98, 95% CI 0.77-1.27, p = 0.899). In AMI patients complicated by CS, the risk of a composite of cardiac death, myocardial infarction, or target vessel revascularization was not significantly different between those treated with DP-DESs and those treated with BP-DESs.Trial registration: RESCUE registry, https://clinicaltrials.gov/ct2/show/NCT02985008 , NCT02985008.

Prediction of In-Hospital Mortality for Ischemic Cardiogenic Shock Requiring Venoarterial Extracorporeal Membrane Oxygenation.

BACKGROUND: Clinical outcome of ischemic cardiogenic shock (CS) requiring extracorporeal membrane oxygenation is highly variable, necessitating appropriate assessment of prognosis. However, a systemic predictive model estimating the mortality of refractory ischemic CS is lacking. The PRECISE (Prediction of In-Hospital Mortality for Patients With Refractory Ischemic Cardiogenic Shock Requiring Veno-Arterial Extracorporeal Membrane Oxygenation Support) score was developed to predict the prognosis of refractory ischemic CS due to acute myocardial infarction. METHODS AND RESULTS: Data were obtained from the multicenter CS registry RESCUE (Retrospective and Prospective Observational Study to Investigate Clinical Outcomes and Efficacy of Left Ventricular Assist Device for Korean Patients With Cardiogenic Shock) that consists of 322 patients with acute myocardial infarction complicated by refractory ischemic CS requiring extracorporeal membrane oxygenation support. Fifteen parameters were selected to assess in-hospital mortality. The developed model was validated internally and externally using an independent external cohort (n=138). Among 322 patients, 138 (42.9%) survived postdischarge. Fifteen predictors were included for model development: age, diastolic blood pressure, hypertension, chronic kidney disease, peak lactic acid, serum creatinine, lowest left ventricular ejection fraction, vasoactive inotropic score, shock to extracorporeal membrane oxygenation insertion time, extracorporeal cardiopulmonary resuscitation, use of intra-aortic balloon pump, continuous renal replacement therapy, mechanical ventilator, successful coronary revascularization, and staged percutaneous coronary intervention. The PRECISE score yielded a high area under the receiver-operating characteristic curve (0.894 [95% CI, 0.860-0.927]). External validation and calibration resulted in competent sensitivity (area under the receiver-operating characteristic curve, 0.895 [95% CI, 0.853-0.930]). CONCLUSIONS: The PRECISE score demonstrated high predictive performance and directly translates into the expected in-hospital mortality rate. The PRECISE score may be used to support clinical decision-making in ischemic CS (www.theprecisescore.com). REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02985008.

Clinical significance of residual ischaemia in acute myocardial infarction complicated by cardiogenic shock undergoing venoarterial-extracorporeal membrane oxygenation.

AIMS: Although culprit-only revascularization during the index procedure has been recommended in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS), the reduction in residual ischaemia is also emphasized to improve clinical outcomes. However, few data are available about the significance of residual ischaemia in patients undergoing mechanical circulatory supports. This study aimed to evaluate the effects of residual ischaemia on clinical outcomes in patients with AMI undergoing venoarterial-extracorporeal membrane oxygenation (VA-ECMO). METHODS AND RESULTS: Patients with AMI with multivessel disease who underwent VA-ECMO due to refractory CS were pooled from the RESCUE and SMC-ECMO registries. The included patients were classified into three groups according to residual ischaemia evaluated using the residual Synergy between percutaneous coronary intervention with Taxus and Cardiac Surgery (SYNTAX) score (rSS): rSS = 0, 0 < rSS ≤ 8, and rSS > 8. The primary outcome was 1-year all-cause death. A total of 408 patients were classified into the rSS = 0 (n = 100, 24.5%), 0 < rSS ≤ 8 (n = 136, 33.3%), and rSS > 8 (n = 172, 42.2%) groups. The cumulative incidence of the primary outcome differed significantly according to rSS (33.9 vs. 55.4 vs. 66.1% for rSS = 0, 0 < rSS ≤ 8, and rSS > 8, respectively, overall P < 0.001). In a multivariable model, rSS was independently associated with the risk of 1-year all-cause death (adjusted hazard ratio 1.03, 95% confidence interval 1.01-1.05, P = 0.003). Conversely, the baseline SYNTAX score was not associated with the risk of the primary outcome. Furthermore, when patients were stratified by rSS, the primary outcome did not differ significantly between the high and low delta SYNTAX score groups. CONCLUSION: In patients with AMI with refractory CS who underwent VA-ECMO, residual ischaemia was associated with an increased risk of 1-year mortality. Future studies are needed to evaluate the efficacy and safety of revascularization strategies to minimize residual ischaemia in patients with CS supported with VA-ECMO. CLINICAL TRIAL REGISTRATION: REtrospective and Prospective Observational Study to Investigate Clinical oUtcomes and Efficacy of Left Ventricular Assist Device for Korean Patients With Cardiogenic Shock (RESCUE), NCT02985008.

Cardiogenic shock complicating acute myocardial infarction and multivessel disease: revascularization strategy according to ischemic territory.

INTRODUCTION AND OBJECTIVES: The association of revascularization strategy with clinical outcomes according to the ischemic territory of nonculprit lesion has not been documented in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS). This study aimed to compare outcomes between culprit-only and immediate multivessel percutaneous coronary intervention (PCI) according to ischemic territory in patients with AMI-CS. METHODS: A total of 536 patients with AMI-CS and multivessel disease from the SMART-RESCUE registry were categorized according to ischemic territory (nonculprit left main/proximal left anterior descending artery [LM/pLAD] vs culprit LM/pLAD vs no LM/pLAD). The primary outcome was a patient-oriented composite endpoint (POCE) consisting of all-cause death, myocardial infarction, rehospitalization due to heart failure, or repeat revascularization at 1 year. RESULTS: Among the total population, 108 patients had nonculprit LM/pLAD, 228 patients had culprit LM/pLAD, and 200 patients had no LM/pLAD, with the risk of POCE being higher in patients with large ischemic territory lesions (53.6% vs 53.4% vs 39.6%; P = .02). Multivessel PCI was associated with a significantly lower risk of POCE compared with culprit-only PCI in patients with nonculprit LM/pLAD (40.7% vs 66.9%; HR, 0.52; 95%CI, 0.29-0.91; P=.02), but not in those with culprit LM/pLAD (P=.46) or no LM/pLAD (P=.47). A significant interaction existed between revascularization strategy and large nonculprit ischemic territory (P=.03). CONCLUSIONS: Large ischemic territory involvement was associated with worse clinical outcomes in patients with AMI-CS and multivessel disease. Immediate multivessel PCI might improve clinical outcomes in patients with a large nonculprit ischemic burden.

Clinical Value of Single-Projection Angiography-Derived FFR in Noninfarct-Related Artery.

BACKGROUND: The Murray law-based quantitative flow ratio (µFR) is an emerging technique that requires only 1 projection of coronary angiography with similar accuracy to quantitative flow ratio (QFR). However, it has not been validated for the evaluation of noninfarct-related artery (non-IRA) in acute myocardial infarction (AMI) settings. Therefore, our study aimed to evaluate the diagnostic accuracy of µFR and the safety of deferring non-IRA lesions with µFR >0.80 in the setting of AMI. METHODS: µFR and QFR were analyzed for non-IRA lesions of patients with AMI enrolled in the FRAME-AMI trial (Fractional Flow Reserve Versus Angiography-Guided Strategy for Management of Non-Infarction Related Artery Stenosis in Patients With Acute Myocardial Infarction), consisting of fractional flow reserve (FFR)-guided percutaneous coronary intervention and angiography-guided percutaneous coronary intervention groups. The diagnostic accuracy of µFR was compared with QFR and FFR. Patients were classified by the non-IRA µFR value of 0.80 as a cutoff value. The primary outcome was a vessel-oriented composite outcome, a composite of cardiac death, non-IRA-related myocardial infarction, and non-IRA-related repeat revascularization. RESULTS: µFR and QFR analyses were feasible in 443 patients (552 lesions). µFR showed acceptable correlation with FFR (R=0.777; P<0.001), comparable C-index with QFR to predict FFR ≤0.80 (µFR versus QFR: 0.926 versus 0.961, P=0.070), and shorter total analysis time (mean, 32.7 versus 186.9 s; P<0.001). Non-IRA with µFR >0.80 and deferred percutaneous coronary intervention had a significantly lower risk of vessel-oriented composite outcome than non-IRA with performed percutaneous coronary intervention (3.4% versus 10.5%; hazard ratio, 0.37 [95% CI, 0.14-0.99]; P=0.048). CONCLUSIONS: In patients with multivessel AMI, µFR of non-IRA showed acceptable diagnostic accuracy comparable to that of QFR to predict FFR ≤0.80. Deferred non-IRA with µFR >0.80 showed a lower risk of vessel-oriented composite outcome than revascularized non-IRA. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02715518.

Drug-Coated Balloon Angioplasty in Patients Undergoing Complex Percutaneous Coronary Intervention.

Background: There are limited clinical data on drug-coated balloon (DCB)-based percutaneous coronary intervention (PCI) compared with drug-eluting stent (DES)-only PCI in patients with complex coronary artery lesions. Objectives: The goal of the current study was to investigate the efficacy of DCB in patients undergoing PCI for complex coronary artery lesions. Methods: From an institutional registry of patients with de novo complex coronary artery lesions, 126 patients treated with DCB-based PCI were compared with 234 propensity score-matched patients treated with DES-only PCI. Complex coronary artery lesions were defined as the presence of at least 1 of the following: bifurcation, chronic total occlusion, unprotected left main disease, long lesion ≥38 mm, multivessel disease, lesion requiring ≥3 devices, or severe calcification. The primary endpoint was target vessel failure (TVF) at 2 years, a composite of cardiac death, target vessel-related myocardial infarction, and target vessel revascularization. Results: Baseline characteristics were comparable between the 2 groups. DCB-based PCI showed a comparable risk of TVF vs DES-based PCI (7.6% vs 8.1%; HR: 0.81; 95% CI: 0.33-1.99; P = 0.638). The risks of cardiac death (5.0% vs 5.7%; HR: 0.78; 95% CI: 0.24-2.49), target vessel-related myocardial infarction (0.9% vs 1.3%; HR: 2.65; 95% CI: 0.26-27.06), and target vessel revascularization (3.5% vs 2.0%; HR: 1.30; 95% CI: 0.30-5.67) were also comparable between the 2 groups. Conclusions: DCB-based PCI showed comparable risks of TVF vs those of DES-only PCI in patients with complex coronary artery lesions. DCB might be considered as a suitable alternative device to DES in patients undergoing complex PCI. (Long-term Outcomes and Prognostic Factors in Patient Undergoing CABG or PCI; NCT03870815).