Effect of Angiotensin Receptor Blocker Dose in Myocardial Infarction With Preserved Left Ventricular Systolic Function.

ABSTRACT: There have been few studies of angiotensin receptor blocker (ARB) dose in myocardial infarction (MI) with preserved left ventricular (LV) systolic function. We evaluated the association of ARB dose with clinical outcomes after MI with preserved LV systolic function. We used MI multicenter registry. Six months after discharge, the ARB dose was indexed to the target ARB doses used in randomized clinical trials and grouped as >0%-25% (n = 2333), >25% of the target dose (n = 1204), and no ARB (n = 1263). The primary outcome was the composite of cardiac death or MI. Univariate analysis showed that mortality of those with any ARB dose was lower than those without ARB therapy. After multivariable adjustment, patients receiving >25% of target dose had a similar risk of cardiac death or MI compared with those receiving ≤25% or no ARB [hazard ratio (HR) 1.05, 95% confidence interval (CI) 0.83-1.33; HR 0.94, 95% CI 0.82-1.08, respectively]. Propensity score analysis also demonstrated that patients with >25% dose had no difference in primary endpoint compared with those ≤25% dose or the no ARB group (HR 1.03, 95% CI 0.79-1.33; HR 0.86, 95% CI 0.64-1.14, respectively). The present study demonstrates that patients treated with >25% of target ARB dose do not have better clinical outcomes than those treated with ≤25% of target ARB dose or those with no ARB dose in MI patients with preserved LV systolic function.

Optimal timing of revascularization for patients with non-ST segment elevation myocardial infarction and severe left ventricular dysfunction.

Optimal timing of revascularization for patients who presented with non-ST segment elevation myocardial infarction (NSTEMI) and severe left ventricular (LV) dysfunction is unclear. A total of 386 NSTEMI patients with severe LV dysfunction from the nationwide, multicenter, and prospective Korea Acute Myocardial Infarction Registry V (KAMIR-V) were enrolled. Severe LV dysfunction was defined as LV ejection fraction ≤ 35%. Patients with cardiogenic shock were excluded. Patients were stratified into two groups: PCI within 24 hours (early invasive group) and PCI over 24 hours (selective invasive group). Primary endpoint was major adverse cardiac and cerebrovascular events (MACCE) including all-cause death, non-fatal MI, repeat revascularization, and stroke at 12 months after index procedure. Early invasive group showed higher incidence of in-hospital death (9.4% vs 3.3%, P = .036) and cardiogenic shock (11.5% vs 4.6%, P = .030) after PCI. Early invasive group also showed higher maximum troponin I level during admission (27.7 ±â€…44.8 ng/mL vs 14.9 ±â€…24.6 ng/mL, P = .001), compared with the selective invasive group. Early invasive group had an increased risk of 12-month MACCE, compared with selective invasive group (25.6% vs 17.1%; adjusted HR = 2.10, 95% CI 1.17-3.77, P = .006). Among NSTEMI patients with severe LV dysfunction, the early invasive strategy did not improve the clinical outcomes. This data supports that an individualized approach may benefit high-risk NSTEMI patients rather than a routine invasive approach.

Clinical effects of hypertension on the mortality of patients with acute myocardial infarction.

The incidence of ischemic heart disease has been increased rapidly in Korea. However, the clinical effects of antecedent hypertension on acute myocardial infarction have not been identified. We assessed the relationship between antecedent hypertension and clinical outcomes in 7,784 patients with acute myocardial infarction in the Korea Acute Myocardial Infarction Registry during one-year follow-up. Diabetes mellitus, hyperlipidemia, cerebrovascular disease, heart failure, and peripheral artery disease were more prevalent in hypertensives (n=3,775) than nonhypertensives (n=4,009). During hospitalization, hypertensive patients suffered from acute renal failure, shock, and cerebrovascular event more frequently than in nonhypertensives. During follow-up of one-year, the incidence of major adverse cardiac events was higher in hypertensives. In multi-variate adjustment, old age, Killip class > or =III, left ventricular ejection fraction <45%, systolic blood pressure <90 mmHg on admission, post procedural TIMI flow grade < or =2, female sex, and history of hypertension were independent predictors for in-hospital mortality. However antecedent hypertension was not significantly associated with one-year mortality. Hypertension at the time of acute myocardial infarction is associated with an increased rate of in-hospital mortality.