Complicating ST-segment Elevation Myocardial Infarction Research Articles

High-degree atrioventricular block complicating ST-segment elevation myocardial infarction in the era of primary percutaneous coronary intervention

Primary percutaneous coronary intervention (pPCI) has replaced thrombolysis as treatment-of-choice for ST-segment elevation myocardial infarction (STEMI). However, the incidence and prognostic significance of high-degree atrioventricular block (HAVB) in STEMI patients in the pPCI era has been only sparsely investigated. The objective of this study was to assess the incidence, predictors and prognostic significance of HAVB in STEMI patients treated with pPCI. This study included 2073 STEMI patients treated with pPCI. The patients were identified through a hospital register and the Danish National Patient Register. Both registers were also used to establish the diagnosis of HAVB. All-cause mortality was the primary endpoint. During a median follow-up of 2.9 years [interquartile range (IQR) 1.8-4.0] 266 patients died. High-degree atrioventricular block was documented in 67 (3.2%) patients of whom 25 died. Significant independent predictors of HAVB included right coronary artery occlusion, age >65 years, female gender, hypertension, and diabetes. The adjusted mortality rate was significantly increased in patients with HAVB compared to patients without HAVB [hazard ratio = 3.14 (95% confidence interval 2.04-4.84), P< 0.001]. A landmark-analysis 30 days post-STEMI showed equal mortality rates in the two groups. The incidence of HAVB in STEMI patients treated with pPCI has been reduced compared with reports from the thrombolytic era. However, despite this improvement high-degree AV block remains a severe prognostic marker in the pPCI era. The mortality rate was only increased within the first 30 days. High-degree atrioventricular block patients who survived beyond this time-point thus had a prognosis equal to patients without HAVB.

Association between advanced Killip class at presentation and impaired myocardial perfusion among patients with ST-segment elevation myocardial infarction treated with primary angioplasty and adjunctive glycoprotein IIb-IIIa inhibitors

Although primary angioplasty has been shown to improve survival as compared with thrombolysis, the outcome is still unsatisfactory in subsets of patients such as those with signs of heart failure at presentation. In fact, although primary angioplasty is able to restore TIMI 3 flow in most patients, suboptimal myocardial reperfusion is observed in a relatively large proportion of patients. The aim of this study was to investigate among patients with ST-segment elevation myocardial infarction undergoing primary angioplasty the association between heart failure at presentation and myocardial perfusion and its implications in terms of survival. Our population is represented by patients undergoing primary angioplasty who are included in the EGYPT database. Congestive heart failure was defined as Killip class >1 at admission. Myocardial perfusion was evaluated by myocardial blush grade and ST-segment resolution. Follow-up data were collected between 30 days and 1 year after primary angioplasty. Detailed data on Killip class at presentation were available in 1,427 of 1,662 patients (86% of the initial population) who represent the final population of this study. Killip class was associated with myocardial perfusion, distal embolization, enzymatic infarct size, predischarge ejection fraction, and 1-year mortality rate. Myocardial blush was an independent predictor of 1-year mortality (hazard ratio 7.44, 95% CI 1.82-30.4, P = .005) in patients with advanced Killip class at presentation. Our study shows that patients with heart failure complicating ST-segment elevation myocardial infarction have impaired myocardial perfusion, which accounts for the poor outcome observed in these patients. Further efforts should be aimed at improving myocardial perfusion, beyond epicardial recanalization, to further improve the outcome of these high-risk patients.

Abstract P188: Impact of Metabolic Crisis on Fatal Outcome in Patients with Cardiogenic Shock Complicating ST-segment Elevation Myocardial Infarction

We investigated the relation of initial metabolic acidemia to in-hospital mortality in patients treated with emergency coronary angioplasty for shock complicating first anterior ST-segment elevation myocardial infarction (STEMI). Methods A total of 23 consecutive patients (17 men, 73±12 years) with Killip class IV class due to anterior STEMI were studied. Using median levels of arterial base excess (BE, −5.8 mmol/L), the patients were divided into high and low BE groups, and both groups were compared regarding microvascular revascularization and clinical outcomes. To evaluate myocardial tissue-level reperfusion, severe microvascular injury was defined by the presence of both angiographic myocardial blush grade 0/1 and less than 30 % resolution of ST-elevation after angioplasty. Results In-hospital mortality was 92 % in the high BE group (−12.0±4.9 mmol/L) as compared with 9 % in the low BE group (−0.9±2.4mmol/L, p=0.0001 vs. high BE group). Baseline clinical and angiographic characteristics were not different between the two groups. Arterial gas analysis showed lower pH and higher levels of lactate in the high BE group than in the low BE group (7.22±0.16 vs. 7.42±0.06, p=0.006, 8.52±4.43 vs. 2.42±1.33, p=0.016). Despite successfully culprit angioplasty in all cases, the incidence of severe microvascular injury was significantly high in the high BE group as compared with the low BE group (83 vs. 36 %, p=0.018). Initial levels of BE showed a significant negative relation to ST-segment resolution (r=0.61, p=0.002). A multivariate regression analysis demonstrated a potent association of initial levels of BE with severe microvascular injury (r 2 =0.341, p=0.015). Conclusions We identified the pivotal association of initial metabolic crisis with severe microvascular reperfusion injury leading to high in-hospital mortality in patients with cardiogenic shock complicating STEMI.

Cardiogenic shock developing in the coronary care unit in patients with ST-elevation myocardial infarction

A relevant proportion of patients with ST-segment elevation myocardial infarction may develop cardiogenic shock after presentation, and the identification of these patients would be very important in order to improve their outcome. The aim of the current study was to identify, among patients in the BLITZ-1, the clinical predictors, and describe the outcome of patients who developed cardiogenic shock during hospitalization. The study was a nationwide survey of patients admitted to a coronary care units for an acute myocardial infarction with or without ST-segment elevation myocardial infarction in October 2001. The 30-day follow-up was conducted by hospital visits and concerned major cardiac events occurred from hospital discharge. A total of 1345 patients presenting with ST-segment elevation myocardial infarction or left bundle branch block/pacemaker were included in this analysis. A total of 97 patients (7.2%) had cardiogenic shock, 26 patients at presentation, whereas 71 patients (73.2%) developed shock during hospital stay. Mortality was 71.8% among patients who developed cardiogenic shock during hospitalization as compared with 65.4% among those who were already in shock upon admission (P = 0.54). By multivariable analysis, we identified Killip class more than 1, lower systolic blood pressure at presentation, older age, unsuccessful reperfusion and diabetes as independent predictors of developing shock during hospitalization. The present study shows that the largest proportion of cardiogenic shock complicating ST-segment elevation myocardial infarction is observed after initial hospitalization, particularly in patients with Killip class more than 1, low systolic blood pressure at presentation and advanced age. The identification of these patients may help in preventing this complication by more aggressive pharmacological therapies, mechanical haemodynamic support, as well as coronary revascularization.

Early invasive versus conservative treatment in patients with failed fibrinolysis—no late survival benefit: The final analysis of the Middlesbrough Early Revascularisation to Limit Infarction (MERLIN) randomized trial

Early (30 days) and midterm (6 months) clinical outcomes in trials comparing rescue angioplasty (rescue percutaneous coronary intervention [rPCI]) with conservative treatment of failed fibrinolysis complicating ST-segment elevation myocardial infarction have shown variable results. Whether early rPCI confers late (up to 3 years) clinical benefits is not known. The MERLIN trial compared rPCI and a conservative strategy in patients with failed fibrinolysis complicating ST-segment elevation myocardial infarction. Three hundred seven patients with electrocardiographic evidence of failure to reperfuse at 60 minutes were included. Patients in cardiogenic shock were excluded. Thirty-day and 1-year results have been reported. Results of 3 years of follow-up are presented. Three-year mortality in the conservative arm and rPCI, respectively, was 16.9% versus 17.6% (P = .9, relative difference [RD] -0.8, 95% CI [-9.3 to 7.8]). Death rates were similar (3.9% vs 3.2%) between 1- and 3-year follow-up, respectively. The incidence of the composite secondary end point of death, reinfarction, stroke, unplanned revascularization, or heart failure was significantly higher in the conservative arm (64.3% vs 49%, P = .01, RD 15.3, 95% CI [4.2-26]). There was no significant difference in the rate of reinfarction (0.7% vs 0.7%) or heart failure (1.3% vs 2.7%) between 1 and 3 years between the conservative and rPCI arms, respectively. The incidence of subsequent unplanned revascularization at 3 years was significantly higher in the conservative arm (33.8% vs 14.4%, P < .01, RD 19.4, 95% CI [10-28.7]), most of which occurred within 1 year; the rates between 1 and 3 years were 3.9% in the conservative arm versus 2% in the rPCI arm. There was a trend toward fewer strokes in the conservative arm at 3 years (conservative arm 2.6% vs rPCI 6.5%, P = .1, RD -3.9%, 95% CI [-9.4 to 0.8]), with similar stroke rates (1.3% vs 1.3%) between 1- and 3-year follow-up. Rescue angioplasty did not confer a late survival advantage at 3 years. The composite end point occurred less often in the rPCI arm mainly because of fewer unplanned revascularization procedures in the early phase of follow-up. The highest risk of clinical events in patients with failed reperfusion is in the first year, beyond which the rate of clinical events is low.

A randomized trial of rescue angioplasty versus a conservative approach for failed fibrinolysis in ST-segment elevation myocardial infarction: The Middlesbrough Early Revascularization to Limit INfarction (MERLIN) trial

ObjectivesWe sought to compare emergency coronary angiography with or without rescue percutaneous coronary intervention (PCI) with conservative treatment in patients with failed fibrinolysis complicating ST-segment elevation myocardial infarction (STEMI). BackgroundMost patients with STEMI receive fibrinolytic therapy and aspirin. The management of failed fibrinolysis is unclear. MethodsA total of 307 patients with STEMI and failed fibrinolysis were randomized to emergency coronary angiography with or without rescue PCI or conservative treatment. ResultsThirty-day all-cause mortality was similar in the rescue and conservative groups (9.8% vs. 11%, p = 0.7, risk difference [RD] 1.2%, 95% confidence interval [CI] −5.8 to 8.3). The composite secondary end point of death/re-infarction/stroke/subsequent revascularization/heart failure occurred less frequently in the rescue group (37.3% vs. 50%, p = 0.02, RD 12.7%, 95% CI 1.6 to 23.5), driven by less subsequent revascularization (6.5% vs. 20.1%, p < 0.01, RD 13.6%, 95% CI 6.2 to 21.4). Re-infarction and clinical heart failure were less common in the rescue group (7.2% vs. 10.4%, p = 0.3, RD 3.2%, 95% CI −3.3 to 9.9; and 24.2% vs. 29.2%, p = 0.3, RD 5.7%, 95% CI −4.3 to 15.6, respectively). Strokes and transfusions were more common in the rescue group (4.6% vs. 0.6%, p = 0.03, RD 3.9%, 95% CI 0.5 to 8.6; and 11.1% vs. 1.3%, p < 0.001, RD 9.8%, 95% CI 4.9 to 19.9, respectively). Left ventricular function at 30 days was the same in the two groups. ConclusionsRescue angioplasty did not improve survival by 30 days, but improved event-free survival, almost completely due to a reduction in subsequent revascularization. Rescue angioplasty was associated with more strokes and more transfusions and did not result in preservation of left ventricular systolic function at 30 days.

Early prevention and management of ischemic heart disease: Focus on hypertension

The purpose of this study was to determine the association of complete heart block (CHB) with outcomes and to examine temporal trends in the incidence and outcomes of CHB complicating ST-segment elevation myocardial infarction (STEMI).There are limited data available on the incidence and outcomes of CHB in STEMI patients who undergo contemporary management.We used the 2003 to 2012 National Inpatient Sample databases to identify all patients age ≥18 years hospitalized with STEMI. Patients with a concomitant diagnosis of CHB were then identified. Multivariable logistic regression was used to analyze the association of CHB with outcomes and to examine the temporal trends in incidence and outcomes of CHB complicating STEMI.Of 2,273,853 patients with STEMI, 49,882 (2.2%) had CHB. The incidence of CHB increased from 2.1% in 2003 to 2.3% in 2012 (adjusted odds ratio [OR] per year: 1.02; 95% confidence interval [CI]: 1.02 to 1.03). STEMI patients with CHB had higher in-hospital mortality than those without CHB (20.4% vs. 8.7%; adjusted OR: 2.47; 95% CI: 2.41 to 2.53). The higher mortality associated with CHB was independent of the location of STEMI; however, the magnitude of this association was greatest in patients with anterior STEMI. In patients with CHB complicating STEMI, although permanent pacemaker implantation rates declined (adjusted OR per year: 0.96; 95% CI: 0.95 to 0.97), in-hospital mortality remained unchanged during the study period (adjusted OR per year: 1.00; 95% CI: 0.99 to 1.01).The incidence of CHB complicating STEMI has increased slightly over the last decade, although the absolute incidence remains quite low. CHB remains associated with higher in-hospital mortality in STEMI patients even in the current era of prompt reperfusion therapy. In patients with CHB complicating STEMI, there was no change in risk-adjusted in-hospital mortality during the study period.