Influence of baseline lipids on effectiveness of pravastatin in the CARE Trial. Cholesterol And Recurrent Events.

OBJECTIVES: We sought to assess the influence of baseline lipid levels on coronary event rates and the effectiveness of pravastatin therapy in the Cholesterol And Recurrent Events (CARE) study. BACKGROUND: The CARE study cohort provided a relatively unique opportunity to examine the relation between lipid levels and clinical events in a post-myocardial infarction (MI) population with relatively low cholesterol and low density lipoprotein (LDL) cholesterol values. METHODS: There were 4,159 patients with a previous infarct and a total cholesterol level <240 mg/dl, LDL cholesterol level 115 to 174 mg/dl and triglyceride level <350 mg/dl randomly allocated to placebo (n=2,078) or pravastatin 40 mg/day (n=2,081). Time to either coronary death or nonfatal MI (primary end point) or to the secondary end point, which included undergoing a coronary revascularization procedure, was determined as a function of baseline lipids (total, LDL, high density lipoprotein [HDL] cholesterol and triglyceride levels). RESULTS: Quartile analysis indicated important effects for LDL cholesterol, in which a higher LDL was associated with greater cardiac event rates (in the placebo group, every 25-mg/dl increment in LDL was associated with a 28% increased risk [5% to 56%, p=0.015]) in the primary event. The differential event rates with respect to baseline LDL cholesterol for placebo and pravastatin groups reduced the difference in clinical outcomes at lower LDL cholesterol levels. In both the placebo and pravastatin groups, an inverse relation between baseline HDL cholesterol and cardiac events was observed (10 mg/dl lower baseline HDL cholesterol level was associated with a 10% [0% to 19%, p=0.046] increase in coronary death or nonfatal MI). CONCLUSIONS: Within the LDL cholesterol levels in CARE (115 to 174 mg/dl), baseline values influenced both the risk of events in the placebo group as well as the clinical effectiveness of pravastatin therapy.

The antianginal efficacy of isosorbide dinitrate therapy is maintained during diuretic treatment.

OBJECTIVES: To determine whether the use of a diuretic would maintain the antianginal efficacy of isosorbide dinitrate during 1 week of therapy. METHODS: During continuous therapy, organic nitrates have a reduction in antianginal effectiveness and cause fluid retention. The study was a randomized, double-blind, placebo-controlled crossover design examining the effect of 1 week of daily treatment with 50 mg hydrochlorothiazide/5 mg amiloride on the antianginal effectiveness of 30 mg isosorbide dinitrate administered every 6 hours. Exercise stress testing was performed before and 3 hours after administration of isosorbide dinitrate at the start and end of the placebo and diuretic treatment phases. RESULTS: The time to onset of angina (475 +/- 35 versus 490 +/- 29 seconds, difference not significant) and to moderate angina after administration of isosorbide dinitrate (542 +/- 40 versus 566 +/- 37 seconds, difference not significant) were similar at the start and end of the diuretic phase of the study but were reduced at the end of the placebo phase (471 +/- 40 versus 410 +/- 40 seconds, p < 0.05 and 531 +/- 38 versus 466 +/- 39 seconds, p < 0.05, respectively). Total exercise time and time to onset of angina 3 hours after administration of isosorbide dinitrate were longer (p < 0.005) at the end of the diuretic phase compared with the end of the placebo phase. Patients gained weight during the placebo phase and lost weight during the diuretic phase of the study. The change in weight was inversely correlated to the change in total exercise time (r = -0.53, p < 0.05). CONCLUSIONS: Patients using a diuretic with isosorbide dinitrate maintain an increased anginal threshold and total exercise time compared with placebo. Weight change is inversely related to exercise duration, and this result is consistent with fluid retention restoring cardiac preload during nitrate use. The increased anginal threshold during concurrent isosorbide dinitrate and diuretic use may be attributable to maintenance of the organic nitrate-induced reductions in cardiac preload.

Right ventricular infarction: two-dimensional echocardiographic evaluation.

Seventeen patients with predominant right ventricular infarction (RVMI) were studied with two-dimensional echocardiography (2DE). On initial 2DE all had abnormal wall motion (AWM), defined as akinesis plus dyskinesis, in the inferior right ventricle (RV), inferior interventricular septum, and inferior left ventricle (LV). The extent of RV vs LV AWM in short-axis sections at mitral, chordal, and papillary levels was 58% vs 29%, 56% vs 38%, and 59% vs 38%, respectively. The calculated topographic extent of AWM was greater in the RV than in the LV (58% vs 36%, p less than 0.05), and the RV/LV ratio (1.65) exceeded (p less than 0.001) unity. Peak creatine phosphokinase levels correlated significantly (p less than 0.001) with the topographic extent of LV AWM (r = 0.79) or RV + LV AWM (r = 0.75). Although all patients had RV dilatation, eight also had LV dilatation. Serial studies detected the cause of mechanical complications (n = 13), mural echo densities suggesting thrombi (LV in six and RV in seven), and persistent AWM in survivors. Thus, 2DE provided diagnostic data, and assessment of RV and LV AWM confirmed predominant RV involvement.

Persistent reduction in left ventricular asynergy in patients with acute myocardial infarction by intravenous infusion of nitroglycerin.

Intravenous nitroglycerin (NG) infusion in patients with acute myocardial infarction (AMI) has been shown to improve left ventricular function and myocardial perfusion and to decrease ischemic injury and creatine kinase (CK) indexes of infarct size. To determine whether early NG infusions in patients with AMI decreases the extent of left ventricular asynergy, we used two-dimensional echocardiography to measure asynergic segments (akinesis and/or dyskinesis) at four serial short-axis levels from base to apex (mitral, M; chordal, C; midpapillary, MP; low papillary, LP) in 22 patients with a first anterior AMI. Patients were randomized between infusions of NG (n = 11) or 5% dextrose in water (controls, n = 11) within 5.6 hr after the onset of pain. NG infusion rates were titrated to lower mean arterial pressure to an average level of 7% below control (but not below 80 mm Hg) and were maintained at this level for the duration of the infusions (39 hr). After NG, left ventricular function improved as left ventricular filling pressure decreased (p less than .005), and sigma ST on precordial ST segment mapping decreased (p less than .001). These parameters did not change in control subjects. Computed CK infarct size was smaller in the NG group than in the control group (p less than .05). Before the infusions, the mean extent of left ventricular asynergy (% left ventricular circumference) were similar in both groups: M, 18% vs 21%; C, 22% vs 23%; MP, 26% vs 24%; LP, 32% vs 29%. In addition, the computed total left ventricular asynergy (% surface area) was also similar for these two groups before therapy (25% vs 25%). There was no change in left ventricular asynergy from pretreatment values by 1 hr and 10 days among control subjects: M, 18% vs 18% vs 17%; C, 22% vs 22%; MP, 26% vs 26% vs 22%; LP, 32% vs 33% vs 33%; total 25% vs 25% vs 24% (multiple measures analysis of variance). In contrast, there was a significant decrease (p less than .001) in left ventricular asynergy from pretreatment values by 1 hr and 10 days with NG: M, 21% vs 10% vs 8%; C, 23% vs 12% vs 10%; MP, 24% vs 13% vs 9%; LP, 29% vs 14% vs 10%; total, 25% vs 12% vs 9%.(ABSTRACT TRUNCATED AT 400 WORDS)

Right ventricular involvement in transmural inferior wall infarction: two-dimensional echocardiographic and clinical correlations.

We used two-dimensional echocardiography to assess asynergy in the right (RV) and left (LV) ventricles in 34 selected patients with electrocardiographic evidence of acute transmural inferior myocardial infarction (IMI) 40 +/- 3 (SE) h from the onset of pain. We measured the extent of asynergy, defined as akinesis and/or dyskinesis, for RV and LV in 4 short axis sections and computed asynergy for both ventricles. The incidence of asynergy was 100% in the inferior LV, 76% in the inferior ventricular septum and 76% in the inferior RV. We found a direct correlation between peak creatine phosphokinase levels and LV asynergy (R = 0.71) or (RV + LV) asynergy (R = 0.72). The asynergy and right heart catheterization data correlated with clinical findings in 4 subgroups identified on the basis of hypotension (systolic blood pressure less than 100 mmHg) and pulmonary congestion, (confirmed radiographically): 1A, extensive biventricular asynergy (32% RV, 32% LV) with hypotension and congestion (N = 10); 1B, predominant RV asynergy (49% RV, 26% LV) with hypotension but no congestion (N = 5); 2A, predominant LV asynergy (7% RV, 26% LV) with congestion (N = 10); 2B less extensive biventricular asynergy (15% RV; 16% LV) and uncomplicated IMI (N = 9). Hypotension identified a high risk group (N = 15) prone to complications and death. The extent of RV asynergy was the third strongest discriminator for hypotension, next to systolic blood pressure and jugular venous pressure. The extent of LV asynergy was the strongest discriminator for pulmonary congestion. Among hypotensive patients, the RV/LV asynergy ratio was the strongest discriminator for pulmonary congestion, being significantly greater in those without congestion than in those with congestion (2.2 vs 1.0, P less than 0.001). The increased RV/LV asynergy ratio may be a useful index for predicting predominant RV infarction in IMI.