The long-term prognosis after myocardial infarction: a five year follow-up study

Meta-analysis of adverse cardiovascular outcomes associated with antecedent hypertension after myocardial infarction

The aim of this study was to investigate the association of antecedent hypertension with adverse cardiovascular outcomes after myocardial infarction. A search of Medline and EMBASE was supplemented by manual searches of the bibliographies of key retrieved reports. The studies were included if they reported antecedent hypertension as a risk factor for adverse outcomes (death, stroke, congestive heart failure, recurrent myocardial infarction) in survivors of myocardial infarctions. Relative risks (RRs) were pooled using a random-effects model, and the robustness of the pooled RRs was evaluated in sensitivity analyses. Cumulative meta-analysis, by chronologic year of study beginning, was also performed. The search yielded 17 studies (n = 56,748 participants) that reported antecedent hypertension with adverse outcomes for survivors of myocardial infarctions. Randomized clinical trials (n = 8) were pooled separately from cohort studies (n = 9). For randomized clinical trials, the pooled RRs were 1.19 (95% confidence interval [CI] 1.13 to 1.26) for all-cause mortality and 1.29 (95% CI 1.09 to 1.53) for cardiovascular disease mortality. For cohort studies, the pooled RRs were 1.46 (95% CI 1.34 to 1.61) for all-cause mortality and 1.54 (95% CI 1.22 to 1.93) for cardiovascular disease mortality. Antecedent hypertension was also consistently associated with an increased risk for stroke, congestive heart failure, and recurrent myocardial infarction. Pooled estimates were robust in sensitivity analysis. In conclusion, antecedent hypertension was associated with adverse outcomes for survivors of myocardial infarctions, the association of antecedent hypertension with all-cause mortality outcomes decreased over time, and this decreased association reflects improved treatment and management of hypertension in more recent years.

Early exercise test vs. clinical parameters in the long-term prognostic management after myocardial infarction

An early exercise test was performed in 317 patients with acute myocardial infarction (AMI). The long-term prognosis was assessed after an average follow-up of 5.7 years. The patients with a small increase in the pressure rate product from rest to maximal exercise and/or wih major ventricular arrhythmias constituted a general prognostic high-risk group. The survival was analyzed further applying the above mentioned exercise parameters in the following clinical subgroups: I) patients with clinical heart failure during hospitalization and/or previous myocardial infarction, II) patients with anterior AMI, III) patients with inferior or indefinite AMI. Within each clinical group there was a highly significant difference in survival between the exercise-determined high-risk and low-risk patients. The exercise parameters were more sensitive and more specific prognostic determinators than the clinical variables. The most striking difference was found in patients with clinical heart failure and/or previous infarction. In this group the exercise-determined high-risk patients had a probability of 5-year survival of 0.238 vs. 0.909 in the corresponding low-risk patients (p less than 0.0005).

Ten year mortality in patients with suspected acute myocardial infarction

OBJECTIVE

To describe the 10 year mortality in patients with suspected acute myocardial infarction.

DESIGN

Follow up of all patients below 76 years of age admitted with acute chest pain to 16 coronary care units participating in the Danish verapamil infarction trial in 1979-81.

SUBJECTS

Of the 5993 patients included, 2586 had definite infarction, 402 had probable infarction, and 3005 did not have infarction.

MAIN OUTCOME MEASURES

Death and cause of death. Standardised mortality ratio (observed mortality/expected mortality in background population).

RESULTS

The estimated 10 year mortalities were 58.8%, 55.5%, and 42.8% in patients with definite, probable, and no infarction, respectively (P < 0.0001). Stratified Cox's analysis identified a hazard ratio for mortality of 1.25 (95% confidence interval 1.08 to 1.44) for probable infarction compared with no infarction and of 1.15 (1.00 to 1.32) for definite compared with probable infarction. The standardised mortality ratio in the first year was 7.1 (6.5 to 7.8) for definite infarction, 5.0 (3.6 to 6.3) for probable infarction, and 4.7 (4.2 to 5.2) for no infarction. From the second year and onwards the annual standardised mortality ratio in the three groups did not differ significantly. Cardiac causes of deaths were recorded in 89%, 84%, and 71% of the deaths in patients with definite, probable, and no infarction, respectively.

CONCLUSIONS

The 10 year mortality of patients with and without infarction is significantly higher than in the background population. Most deaths are caused by coronary heart disease, and these patients should consequently be further evaluated at the time of discharge and followed up closely.

Determinants of 6-month mortality in survivors of myocardial infarction after thrombolysis. Results of the GISSI-2 data base. The Ad hoc Working Group of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI)-2 Data Base

BACKGROUND

Current knowledge of risk assessment in survivors of myocardial infarction is largely based on data gathered before the advent of thrombolysis. It must be determined whether and to what extent available information and proposed criteria of prognostication are applicable in the thrombolytic era.

METHODS AND RESULTS

We reassessed risk prediction in the 10,219 survivors of myocardial infarction with follow-up data available (ie, 98% of the total) who had been enrolled in the GISSI-2 trial, relying on a set of prespecified variables. The 3.5% 6-month all-cause mortality rate of these patients compared with the higher value of 4.6% found in the corresponding GISSI-1 cohort, originally allocated to streptokinase therapy, indicates a 24% reduction in postdischarge 6-month mortality. On multivariate analysis (Cox model), the following variables were predictors of 6-month all-cause mortality: ineligibility for exercise test for both cardiac (relative risk [RR], 3.30; 95% confidence interval [CI], 2.36-4.62) and noncardiac reasons (RR, 3.28; 95% CI, 2.23-4.72), early left ventricular failure (RR, 2.41; 95% CI, 1.87-3.09), echocardiographic evidence of recovery phase left ventricular dysfunction (RR, 2.30; 95% CI, 1.78-2.98), advanced (more than 70 years) age (RR, 1.81; 95% CI, 1.43-2.30), electrical instability (ie, frequent and/or complex ventricular arrhythmias) (RR, 1.70; 95% CI, 1.32-2.19), late left ventricular failure (RR, 1.54; 95% CI, 1.17-2.03), previous myocardial infarction (RR, 1.47; 95% CI, 1.14-1.89), and a history of treated hypertension (RR, 1.32; 95% CI, 1.05-1.65). Early post-myocardial infarction angina, a positive exercise test, female sex, history of angina, history of insulin-dependent diabetes, and anterior site of myocardial infarction were not risk predictors. On further multivariate analysis, performed on 8315 patients with the echocardiographic indicator of left ventricular dysfunction available, only previous myocardial infarction was not retained as an independent risk predictor.

CONCLUSIONS

A decline in 6-month mortality of myocardial infarction survivors, seen within 6 hours of symptom onset, has been observed in recent years. Ineligibility for exercise test, early left ventricular failure, and recovery-phase left ventricular dysfunction are the most powerful (RR, > 2) predictors of 6-month mortality among patients recovering from myocardial infarction after thrombolysis. Qualitative variables reflecting residual myocardial ischemia do not appear to be risk predictors. The lack of an independent adverse influence of early post-myocardial infarction angina on 6-month survival represents a major difference between this study and those of the prethrombolytic era.

Heart rate and beta-adrenergic mechanisms in acute myocardial infarction

Increased heart rate is an independent predictor of mortality in patients with acute myocardial infarction. Elevated heart rate is due to increased sympathetic activity and/or decreased parasympathetic activity. In placebo-controlled trials beta-blockers are known to reduce mortality as well as morbidity and these effects are most evident among patients with elevated heart rate. Studies on circadian variation have demonstrated that there is an increased sympathetic activity in the morning as well as a more frequent onset of ischemic attacked including acute myocardial infarction and sudden death. There seems to be a close relationship between increased sympathetic activity and the onset of ischemic events which can be prevented by prophylactic institution of a beta-blocker.

Outlook after acute myocardial infarction in the very elderly compared with that in patients aged 65 to 75 years

Little is known concerning late outcome and prognostic factors after acute myocardial infarction in the very elderly (greater than 75 years of age). Accordingly, this study compared the clinical course and mortality rate for up to 1 year in a large multicenter data base that included 702 patients greater than 75 years of age (mean +/- SD 81 +/- 4 years), with a less elderly subset of 1,321 patients between 65 and 75 years of age (mean 70 +/- 3 years). The postdischarge 1 year cardiac mortality rate was 17.6% for those greater than 75 years of age compared with 12.0% for patients between 65 and 75 years of age (p less than 0.01). There were differences in the prevalence of several factors, including female gender, history of angina pectoris, history of congestive heart failure, smoking habits and incidence of congestive heart failure during hospitalization. Multivariate analyses of predictors of cardiac death in hospital survivors selected different factors as important in the two age subgroups; age was selected in the 65 to 75 year age group but was not an independent predictor in the very elderly. The survival curves beginning at day 10 for patients 65 to 75 and in those greater than 75 years old were similar for up to 90 days but diverged later. In the very elderly, 63% of late cardiac deaths were sudden or due to new myocardial infarction, similar to the causes of 67% of deaths in the younger age group.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of heart rate on mortality after acute myocardial infarction

Elevated heart rate (HR) during hospitalization and after discharge has been predictive of death in patients with acute myocardial infarction (AMI), but whether this association is primarily due to associated cardiac failure is unknown. The major purpose of this study was to characterize in 1,807 patients with AMI admitted into a multicenter study the relation of HR to in-hospital, after discharge and total mortality from day 2 to 1 year in patients with and without heart failure. HR was examined on admission at maximum level in the coronary care unit, and at hospital discharge. Both in-hospital and postdischarge mortality increased with increasing admission HR, and total mortality (day 2 to 1 year) was 15% for patients with an admission HR between 50 and 60 beats/min, 41% for HR greater than 90 beats/min and 48% for HR greater than or equal to 110 beats/min. Mortality from hospital discharge to 1 year was similarly related to maximal HR in the coronary care unit and to HR at discharge. In patients with severe heart failure (grade 3 or 4 pulmonary congestion on chest x-ray, or shock), cumulative mortality was high regardless of the level of admission HR (range 61 to 68%). However, in patients with pulmonary venous congestion of grade 2, cumulative mortality for patients with admission HR greater than or equal to 90 beats/min was over twice as high as that in patients with admission HR less than 90 beats/min (39 vs 18%, respectively); the same trend was evident in patients with absent to mild heart failure (mortality 18 vs 10%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Prognosis in survivors of acute myocardial infarction occurring at age 70 years or older

To identify prognostic factors in elderly persons who have survived acute myocardial infarction, 113 patients, aged 70 to 91 years (median 76), were followed for an average of 122 months (range 94 to 170). Eighty-four patients died, 61 (73%) from coronary artery disease. Overall mortality rates were 20.4% at 1 year, 30.1% at 2 years, 31.9% at 3 years, 45.1% at 4 years, 51.3% at 5 years and 69% at 10 years. Almost half (44%) of all deaths from coronary causes occurred in the first 2 years. Univariate analysis of 21 historical and clinical variables found several of prognostic significance: age, prior myocardial infarction, previous diastolic hypertension, history of diabetes mellitus, history of heart failure, presence of rales above the scapula, ventricular gallop, Killip class, cardiomegaly on admission chest x-ray and prescribing digitalis or diuretic at discharge. When these prognostic factors were entered into multivariate analysis, only Killip class (p less than 0.001) emerged as an independent predictor of survival.

Risk factors and prognosis after discharge for patients admitted because of suspected acute myocardial infarction with and without confirmed diagnosis

The prognosis regarding cardiac events--acute myocardial infarction (AMI) or cardiac death after discharge--was evaluated in 257 patients admitted because of suspected AMI due to chest pain, but in whom AMI was not confirmed (non-AMI patients). The findings and patient prognoses were compared with those of 275 patients with confirmed AMI. All patients were younger than 76 years and free of severe chronic diseases, and no cause of chest pain other than possible ischemic heart disease was found. The patients were followed for cardiac events for 11 to 24 months (median 14). The prognoses for the non-AMI patients were significantly better than those for the AMI patients (p = 0.05). The proportion without a cardiac event after 1 year was estimated at 91% and 86%, respectively. In the non-AMI patients, angina pectoris, previous AMI and electrocardiographic changes on admission (intraventricular block and permanent or transient ST-T changes) were significant predictors of cardiac events by univariate and multivariate analysis. In the AMI patients, female gender, heart failure, previous AMI and angina pectoris were significant predictors of cardiac events by univariate analysis. With use of multivariate analysis, female gender, heart failure and angina pectoris were independent predictors of cardiac events. Thus, non-AMI patients admitted with chest pain have a high risk of cardiac events after discharge. The risk is highest when there is evidence of coronary artery disease (electrocardiographic changes on admission and angina pectoris or previous AMI.

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.

Significance of haemodynamic variables in coronary care unit for prediction of survival after acute myocardial infarction

In order to assess the value of haemodynamic monitoring in the coronary care unit for long term prognosis after recovery of an acute myocardial infarction, the records of two groups of consecutive patients were reviewed retrospectively. From 254 patients, 32 (13%) died in the hospital and nine patients had to be excluded from subsequent follow-up for various reasons. Four year mortality among the 213 patients who were discharged from the hospital and could be followed up was 26%. Of the haemodynamic variables measured on admission a high pulmonary capillary wedge pressure, exceeding 18 mmHg, and a low mixed venous oxygen saturation, less than 60%, were not only associated with a high hospital but also with a high four year mortality, whereas a low systolic blood pressure (less than 100 mmHg), an important prognosticator during admission to hospital, was only of minor significance thereafter. A negative value on admission of a specific index 0.24 X systolic blood pressure (mmHg) -0.217 X pulmonary capillary wedge pressure (mmHg)+0.234 X mixed venous oxygen saturation (%)-13.1 developed for the prediction of short term survival was also associated with a much higher four year mortality than a positive value. Low cardiac index on admission could be correlated with high mortality during the first two years after discharge, whereas only 9% of patients with a higher cardiac index died. Haemodynamic monitoring in the coronary care unit is thus not only relevant for the immediate prognosis, but a high mortality risk during hospital stay persists for several years after discharge.

Evaluation of prognosis one year after myocardial infarction

Three multivariate methods for predicting death within 1 year for patients discharged after acute myocardial infarction were evaluated: Cox model, discriminant function analysis and recursive partitioning. Discriminant function analysis was utilized to predict a new myocardial infarction (any new or nonfatal infarction). A Cox classification model developed in a population of 260 patients (group 1) discharged after myocardial infarction was tested in 886 patients from the same institution (group 2) and 582 patients from another institution (group 3). Discriminant function analysis and recursive partitioning were developed in group 2 and tested in group 3. Data gathered during the entire period of hospitalization were utilized. The important variables (ordered as selected by the analyses) for the end point death were: heart failure, ventricular tachycardia and atrioventricular block in the Cox model and heart failure, previous myocardial infarction, age and ventricular premature beats in the discriminant function analysis. For the end point new myocardial infarction, the important variables were: previous myocardial infarction, heart failure, extension of infarction during the acute phase and infarct site. For predicting death and survival within 1 year, each of the three schemes was comparable. For estimating the actual risk of death, the Cox model was best. Recursive partitioning had the advantage of using only one variable--heart failure. Total correct classification ranged from 65.4 (Cox model) to 71.6% (discriminant function analysis) for the original population (groups 1 and 2) and from 47.9 (discriminant function analysis) to 54.3% (recursive partioning) when the schemes were tested in patients in group 3. The Cox model and discriminant function analysis were able to correctly predict over half of the new infarctions within 1 year.