Prognostic value of peak exercise systolic blood pressure on long-term survival after myocardial infarction

This study examined the association between peak exercise systolic blood pressure and other exercise test parameters and the long-term (19-year) survival of 625 patients with myocardial infarction who were original participants of the National Exercise and Heart Disease Project, a 3-year (1976 to 1979) multicenter randomized exercise clinical trial. Results show that low peak exercise systolic blood pressure (< or =140 mm Hg) was associated with increased mortality throughout the 19 years of follow-up, and men with this finding obtained no survival benefit from participating in an exercise program.     

Prediction of late mortality after myocardial infarction from variables measured at different times during hospitalization

The long-term prognostic importance of sets of variables from different times in the hospital course after acute myocardial infarction was examined in 818 patients discharged from the hospital. Cardiac mortality during the first year after discharge was 11.1 %. For the end point death within 1 year after admission, discriminant function analysis identified 5 important factors from the history and the first 24 hours of hospitalization: maximal level of blood urea nitrogen, previous myocardial infarction, age, displaced left ventricular apex (abnormal apex) on physical examination, and sinus bradycardia (negative correlation). When data from the entire hospitalization were included, extension of infarction and maximal heart rate were also selected. When variables obtained at discharge were included, only the presence of S₃ gallop and abnormal apex were selected. In subgroups of patients, neither the left ventricular ejection fraction nor the presence of complex ventricular arrhythmias during a 24-hour ambulatory monitoring were independent predictors. Correct prediction was similar for each analysis, with 55 to 60% of the deaths and 79 to 81 % of survivors correctly identified. The high-risk group consisted of 25 % of the patients with 28 to 30 % predictive value for death in the first year. In conclusion, outcome up to 1 year after acute myocardial infarction can be predicted early after admission. Addition of more information later during the hospitalization and at discharge did not improve correct prediction and may be redundant for prognostic evaluation.     

Prognostic value of an electrocardiographic sign in acute myocardial infarction

An ECG sign of infarction (M-complex) is presented, together with its relationship to an increased frequency of complications and to a higher mortality rate. This sign appeared in 58 cases (21 per cent) out of a total of 275 patients. Thromboembolism and “cardiogenic shock” were very significantly frequent (P < 0.001) in these 58 patients (M group) as compared with the remaining 217 patients (non-M group). Cardiomegaly and congestive cardiac failure occurred more often when this complex was in Leads V₄ or V₅. In both the groups, cardiomegaly was often associated with a lateral extension (V₅ to V₆) of the infarction.     

Prognostic value of baroreflex sensitivity testing after acute myocardial infarction.

BACKGROUND--Disturbances of autonomic function are recognised in both the acute and convalescent phases of myocardial infarction. Recent studies have suggested that disordered autonomic function, particularly the loss of protective vagal reflexes, is associated with an increased incidence of arrhythmic deaths. The purpose of this study was to compare the value of differing prognostic indicators with measures of autonomic function and to assess the safety of arterial baroreflex testing early after infarction. METHODS--As part of a prospective trial of risk stratification in post-infarction patients arterial baroreflex sensitivity, heart rate variability, long term electrocardiographic recordings, exercise stress testing, and ejection fraction were recorded between days 7 and 10 in 122 patients with acute myocardial infarction. RESULTS--During a one year follow up period there were 10 arrhythmic events. Baroreflex sensitivity was appreciably reduced in these patients suffering arrhythmic events (1.73 SD (1.49) v 7.83 (4.5) ms/mm hg, 95% confidence interval (CI) 4.8 to 7.3, p = 0.0001). Significant correlations were noted with age (r = -0.68, p less than 0.001) but not left ventricular function. When baroreflex sensitivity was adjusted for the effects of age and ventricular function baroreflex sensitivity was still considerably reduced in the arrhythmic group (2.1 v 7.57 ms/mm Hg, p less than 0.0001). Depressed baroreflex sensitivity carried the highest relative risk for arrhythmic events (23.1, 95% CI 7.7 to 69.2) and was superior to other prognostic variables including left ventricular function (10.4, 95% CI 3.3 to 32.6) and heart rate variability (10.1, 95% CI 5.6 to 18.1). No major complications were noted with baroreflex testing and in particular no patients developed ischaemic or arrhythmic symptoms during the procedure. CONCLUSIONS--Disordered autonomic function as measured by depressed baroreflex sensitivity or reduced heart rate variability was associated with an increase incidence of arrhythmic events in post-infarction patients. Baroreflex testing can be safely performed in the immediate post-infarction period.     

Prognostic value of predischarge 2-dimensional echocardiogram after acute myocardial infarction

The prognostic value of a 2-dimensional echocardiogram (2-D echo) was determined in 46 patients (32 men and 14 women) who survived an acute myocardial infarction (MI) from November 1979 to December 1980. The mean age of the patients was 61 years (range 36 to 92). The MI was anterior in 21, inferior in 22 and indeterminate in 3; it was transmural in 31 and nontransmural in 15. A 2-D echo was obtained 10 to 15 days after the MI--that is, 1 to 3 days before hospital discharge. A wall motion score index (WMSI) was derived with the use of a 14-segment model of the left ventricle. Each segment was assigned a number corresponding to its wall motion (0 = hyperkinetic, 1 = normal, 2 = hypokinetic, 3 = akinetic, 4 = dyskinetic and 5 = aneurysm) and the WMSI was calculated by dividing the sum of these numbers by the number of segments visualized (1.0 = normal wall motion). During a mean follow-up of 21 months (range 15 to 28), 17 patients had a complication: death, recurrence of MI, congestive heart failure of New York Heart Association class III or IV, or angina graded New York Heart Association class III or IV. Patients with compared to those without complications had a significantly higher WMSI (2.2 +/- 0.4 and 1.7 +/- 0.5, p less than 0.005). The difference in WMSI between those who died and those who survived was not significant because of the small number of deaths.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prognostic value of osteoprotegerin in heart failure after acute myocardial infarction

OBJECTIVES: We sought to determine the relationship between osteoprotegerin (OPG) and clinical outcomes in patients with heart failure (HF) after acute myocardial infarction (AMI). BACKGROUND: Arterial calcification is a prominent feature of arterial atherosclerosis and is associated with the occurrence of AMI. Osteoprotegerin is a recently discovered member of the tumor necrosis superfamily that may link the skeletal with the vascular system. METHODS: We assayed plasma OPG levels in 234 patients with AMI complicated with HF and their relation to adverse outcomes during follow-up in patients randomly assigned to angiotensin-converting enzyme inhibition or angiotensin II antagonism. Blood was sampled at baseline (median three days after AMI), one month, and at one and two years. RESULTS: Elevated plasma levels of OPG at baseline were associated with adverse outcomes during a median of 27 months follow-up; OPG remained an independent prognostic indicator also after adjustment for other known predictors of mortality and cardiovascular events after AMI (e.g., creatinine clearance, N-terminal B-type natriuretic peptide, high-sensitivity C-reactive protein). In non-survivors, plasma OPG levels were persistently elevated during longitudinal testing, suggesting that OPG may be of value for monitoring patients at risk. CONCLUSIONS: Osteoprotegerin is a novel marker for cardiovascular mortality and clinical events in patients with AMI complicated with HF. These findings are compatible with the hypothesis suggesting a possible association between mediators of bone homeostasis and cardiovascular disease.     

Prognostic value of baroreflex sensitivity testing after acute myocardial infarction.

BACKGROUND--Disturbances of autonomic function are recognised in both the acute and convalescent phases of myocardial infarction. Recent studies have suggested that disordered autonomic function, particularly the loss of protective vagal reflexes, is associated with an increased incidence of arrhythmic deaths. The purpose of this study was to compare the value of differing prognostic indicators with measures of autonomic function and to assess the safety of arterial baroreflex testing early after infarction. METHODS--As part of a prospective trial of risk stratification in post-infarction patients arterial baroreflex sensitivity, heart rate variability, long term electrocardiographic recordings, exercise stress testing, and ejection fraction were recorded between days 7 and 10 in 122 patients with acute myocardial infarction. RESULTS--During a one year follow up period there were 10 arrhythmic events. Baroreflex sensitivity was appreciably reduced in these patients suffering arrhythmic events (1.73 SD (1.49) v 7.83 (4.5) ms/mm hg, 95% confidence interval (CI) 4.8 to 7.3, p = 0.0001). Significant correlations were noted with age (r = -0.68, p less than 0.001) but not left ventricular function. When baroreflex sensitivity was adjusted for the effects of age and ventricular function baroreflex sensitivity was still considerably reduced in the arrhythmic group (2.1 v 7.57 ms/mm Hg, p less than 0.0001). Depressed baroreflex sensitivity carried the highest relative risk for arrhythmic events (23.1, 95% CI 7.7 to 69.2) and was superior to other prognostic variables including left ventricular function (10.4, 95% CI 3.3 to 32.6) and heart rate variability (10.1, 95% CI 5.6 to 18.1). No major complications were noted with baroreflex testing and in particular no patients developed ischaemic or arrhythmic symptoms during the procedure. CONCLUSIONS--Disordered autonomic function as measured by depressed baroreflex sensitivity or reduced heart rate variability was associated with an increase incidence of arrhythmic events in post-infarction patients. Baroreflex testing can be safely performed in the immediate post-infarction period.     

Significance of abnormal blood pressure response during exercise-induced myocardial dysfunction after recent acute myocardial infarction

The relation between exercise left ventricular ejection fraction and blood pressure (BP) responses after an acute myocardial infarction (AMI) was investigated. Twenty-eight to 37 days after an uncomplicated AMI, 224 consecutive patients underwent exercise radionuclide angiography in the 40 degrees semisupine position. In 180 patients (group A, 80%), BP increased more than 5 mm Hg every stage; in 44 patients, BP responses were abnormal; in 33 (group B, 15%), BP did not increase during 2 stages; in 11 (group C, 5%), it decreased more than 5 mm Hg after an initial increase. Ejection fraction did not differ significantly among the 3 groups at rest (51 +/- 13 in group A, 50 +/- 18 in group B, 47 +/- 13 in group C [difference not significant]) or at peak exercise (51 +/- 16% in group A, 46 +/- 19% in group B, and 43 +/- 16% in group C, [difference not significant]). Exercise-induced left ventricular failure or hemodynamic decompensation occurred in 22 patients. In these patients, ejection fraction at rest was 44 +/- 19% and decreased to 35 +/- 16% (p less than 0.05) with exercise. Only 9 of these patients (41%) had abnormal BP responses, with the other 13 (59%) showing a normal BP responses. The The 35 patients with abnormal BP responses in the absence of hemodynamic decompensation were asymptomatic, terminating exercise because of fatigue. The ejection fraction at rest and during exercise in these patients was similar to that in patients with normal BP responses.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prognostic value of white blood cell count in acute myocardial infarction: long-term mortality

INTRODUCTION AND OBJECTIVES: Although traditionally an elevated white blood cell count (WBC), an indicator of systemic inflammation, has been accepted as part of the healing response following acute myocardial infarction (AMI), it has frequently been shown to be a predictor of adverse cardiovascular events. The present study was designed to assess the association between WBC and long-term mortality in AMI patients either with ST-segment elevation (STEMI) or without ST-segment elevation (non-STEMI). Patients and method. The study included 1118 consecutive patients who were admitted with the diagnosis of AMI: 569 non-STEMI and 549 STEMI. The WBC was measured in the 24 hours following admission. Patients were divided into 3 groups: WBC1 (count, <10 x 103 cells/mL), WBC2 (count, 10-14.9 x 10(3) cells/mL), and WBC3 (count, > or =15x10(3) cells/mL). All-cause mortality was recorded during a median follow-up period of 10+/-2 months. The relationship between WBC and mortality was assessed by Cox regression analysis for both types of AMI. RESULTS: Long-term mortality during follow-up was 18.5% in non-STEMI patients and 19.9% in STEMI patients. In non-STEMI patients, the adjusted hazard ratios for those in the WBC3 and WBC2 groups compared with those in the WBC1 group were 2.07 (1.08-3.94; P=.027) and 1.61 (1.03-2.51; P=.036), respectively. The corresponding figures in STEMI patients were 2.07 (1.13-3.76; P=.017) and 2.22 (1.35-3.63; P=.002), respectively. CONCLUSIONS: WBC on admission was an independent predictor of long-term mortality in both non-STEMI and STEMI patients.     

Prognostic value of exercise-induced QT dispersion in patients after acute myocardial infarction

BACKGROUND: Electrocardiographic exercise tests are widely recommended for patients before discharge after myocardial infarction, what justify the search for new variables which may improve their prognostic value. QT dispersion in 12 lead ECG reflects the heterogeneity of ventricular repolarisation. Increased QT dispersion is a noninvasive marker of ischaemia and electrical instability. AIM: Evaluation of the prognostic value of exercise-induced changes of QT dispersion in patients after an acute myocardial infarction. METHODS: Heart rate limited treadmill exercise test according to modified Bruce was performed 14+/-5 days after infarction in 77 patients (age 56+/-11,8 female). QT dispersion was measured at rest and on peak exercise. Patients were followed up for mean 88 months. RESULTS: QT dispersion was higher at peak exercise in those patients who died due to cardiovascular causes (n=8) or suffered from non-fatal myocardial infarction during follow-up (n=15), than in remaining group (71+/-20 vs 58+/-22 msec, p<0.01). At rest QT dispersion was similar in both groups (64+/-17 vs 66+/-20 msec, NS). CONCLUSIONS: The lack of an exercise-induced decrease in QT dispersion identifies a subgroup of patients after myocardial infarction with a poor long-term prognosis.     

Prognostic value of myocardial viability detected by myocardial contrast echocardiography early after acute myocardial infarction.

OBJECTIVES: This study sought to determine whether residual myocardial viability determined by myocardial contrast echocardiography (MCE) after acute myocardial infarction (AMI) can predict hard cardiac events. BACKGROUND: Myocardial viability detected by MCE has been shown to predict recovery of left ventricular (LV) function in patients with AMI. However, to date no study has shown its value in predicting major adverse outcomes in AMI patients after thrombolysis. METHODS: Accordingly, 99 stable patients underwent low-power MCE at 7 +/- 2 days after AMI. Contrast defect index (CDI) was obtained by adding contrast scores (1 = homogenous; 2 = reduced; 3 = minimal/absent opacification) in all 16 LV segments divided by 16. At discharge, 65 (68%) patients had either undergone or were scheduled for revascularization independent of the MCE result. The patients were subsequently followed up for cardiac death and nonfatal AMI. RESULTS: Of the 99 patients, 95 were available for follow-up. Of these, 86 (87%) underwent thrombolysis. During the follow-up time of 46 +/- 16 months, there were 15 (16%) events (8 cardiac deaths and 7 nonfatal AMIs). Among the clinical, biochemical, electrocardiographic, echocardiographic, and coronary arteriographic markers of prognosis, the extent of residual myocardial viability was an independent predictor of cardiac death (p = 0.01) and cardiac death or AMI (p = 0.002). A CDI of < or = 1.86 and < or = 1.67 predicted survival and survival or absence of recurrent AMI in 99% and 95% of the patients, respectively. CONCLUSIONS: The extent of residual myocardial viability predicted by MCE is a powerful independent predictor of hard cardiac events in patients after AMI.     

Secondary prevention trials after acute myocardial infarction

Of those patients who reach the hospital after an acute myocardial infarction, 18% die during their stay and 85% to 90% of the remainder will eventually die of coronary artery disease. Several secondary preventive approaches have been made to prolong life in these patients. Long-term controlled trials involving nonsurgical measures and at least 100 patients will be reviewed. Lipid-lowering regimens have shown no demonstrable effect on survival over a 4- to 6-year period but show some benefit with respect to nonfatal infarction. Survival was not improved essentially by anticoagulants, antiarrhythmic agents or calcium channel blockers, although new trials are underway that might clarify their role. Platelet-active drugs achieved little reduction in mortality but showed benefit in nonfatal infarction (30% reduction with aspirin). Pooled data on physical exercise programs demonstrated a 15% benefit on mortality but larger trials are required to confirm this. The data on beta blockers (particularly those without intrinsic sympathomimetic activity) show that these drugs improve long-term survival after myocardial infarction, reducing all-cause mortality by as much as 25% to 30%. Larger trials are necessary to detect statistically significant reductions in mortality both overall and in selected subgroups of patients.     

Prognostic value of stress-gated Tc-99m sestamibi SPECT after acute myocardial infarction

Stress-gated technetium-99m (Tc-99 m) sestamibi single-photon emission computed tomography (SPECT) is used to risk stratify patients after acute myocardial infarction (AMI). In clinical practice, results of this test are used primarily to identify patients with myocardial ischemia for intervention. The value of this test to risk stratify patients with AMI not at high ischemic risk has not been addressed. More than 1-year follow-up was undertaken in 124 patients who underwent predischarge gated Tc-99m sestamibi SPECT studies and who did not undergo subsequent revascularization. Clinical variables and test-derived variables were evaluated to predict cardiac death, recurrent AMI, and hospitalization for unstable angina, congestive heart failure, or coronary revascularization. Independent predictors by multivariate analysis for cardiac death or recurrent AMI were a history of prior AMI (relative risk [RR] = 5.32, confidence interval [CI] 2.17 to 12.96), a low exercise capacity (RR = 6.84, CI 1.99 to 23.48), and left ventricular (LV) ejection fraction (EF) <40% (RR = 2.63, CI 1.04 to 6.38). The incidence of cardiac death or recurrent AMI was 29.8% in patients with a low exercise capacity versus 4.5% in those with good exercise capacity, and 38.1% in patients with LVEF <40% versus 9.4% in those with LVEF >40%. Independent predictors of cardiac death, AMI, or hospitalization for unstable angina, congestive heart failure, or revascularization were a history of prior AMI (RR = 2.24, CI 1.11 to 4.50) and LVEF <40% (RR = 3.13, CI 1.64 to 5.95). Among patients followed after AMI without revascularization Tc-99m sestamibi SPECT can identify a high-risk subset. The strongest independent predictors are poor exercise capacity and LVEF < 40%.