Deaths and non-fatal reinfarctions during two years' follow-up after myocardial infarction

Methodological aspects in the design of secondary prevention trials

The aim of a secondary preventive trial is to produce results that may serve as a basis for therapeutic recommendations to other patients. The natural history of a disease studied including the mortality and reinfarction rate must be known and taken into consideration. The patients should be recruited without selection. By comparing the placebo mortality with expected levels the representativeness of patients can be assessed. One type of treatment can be expected to give different results in different groups of patients with the same disease, thus, prognostic prospective stratification may increase the value of comparisons and conclusions. The registration of end-points should preferably be done by a separate independent organization. Carefully classified specific mortality may be used as a major end-point in addition to total mortality. Similarly, different modes of deaths, e.g. sudden death, may be used if reliable definitions are used. Confounding factors are often difficult to isolate and identify and may have profound effects on the interpretation of a study. In all studies it is mandatory that the patient characteristics on entry do not differ between the different treatment groups. Concomitant treatment should be administered according to standardized criteria. The drop-out rate should be kept at a minimum. The possibility of generalization decreases with increasing drop-out rate. If the follow-up time becomes too long it is likely that at some time the relative benefit becomes less. Since the proportion of non-cardiovascular deaths increases with follow-up and age it may be critical to decide on the relevant follow-up time.

Clinical features in patients with recurrent myocardial infarction

A retrospective investigation of 420 patients who had survived the acute phase of myocardial infarction revealed 63 reinfarctions (in 57 patients) within three months. Twenty-eight patients died without reinfarction during the same period, and 335 survived three months without reinfarction. The reinfarction patients were significantly more often women, had more frequently a history of previous myocardial infarction and hypertension, and their myocardial infarctions were more often non-transmural and localized to the anterior wall of the heart. The ECG of each patient that was registered nearest prior to the reinfarction during hospitalization or prior to discharge showed more often negative T-waves.

Prediction of cardiovascular deaths and non-fatal reinfarctions after myocardial infarction

The present study concerns the development and validation of a logistic multivariate prognostic function in patients followed for two years after myocardial infarction. The patients studied constituted at least 90% of all cases in a total community--the City of Göteborg, Sweden. Using a multivariate logistic function with 7 variables, based on 30 cardiovascular deaths during two years after discharge from hospital among 292 men with first infarction, breathlessness at onset of symptoms of infarction, SGOT quartile, left heart failure, relative heart size, atrial fibrillation, a history of hypertension, and AV block recorded during the hospital phase were the most important variables. The first five of these variables made significant contributions (p less than 0.01) to the predictive power. The predictive capacity was confirmed in an independent series of 195 men with first infarction, among whom 17 cardiovascular deaths occurred. Around 60% of the total cardiovascular mortality was concentrated in the highest risk quintile. Deaths from non-cardiovascular causes were predicted less efficiently. Non-fatal recurrences could not be predicted by the present model. Thus, the function can predict the excess risk of mortality but not the excess risk of reinfarction during two years among men after an initial myocardial infarction.

Myocardial infarction in Malmö during the 10-year period 1963--1972

Myocardial infarctions in Malmö during the 10-year period 1963--1972 have been studied. The mortality from myocardial infarction decreased significantly among men during this period but not among women. The incidence of hospital-treated infarction increased significantly among men, mainly due to an increase in primary infarctions. The one-year survival in this hospital material did not improve during the period. The number of days of sick-leave during 12 months before primary infarction was significantly higher than expected. The duration of sick-leave during the year after primary infarction remained unchanged throughout the period. The mortality figures relate to all age groups, comprising 2 111 men and 1 409 women. The hospital incidence relates to men and women aged 65 years or below and comprises 1 323 men and 279 women during the period concerned. The reduced mortality and increased incidence of hospital-treated infarction are probaby explained by the fact that more men seek hospital treatment, leading to a better prognosis. The long duration of sick-leave after infarction is probably due to causes other than strictly medical factors.

Cost-benefit aspects of post-myocardial infarction intervention

After myocardial infarction the mortality during the first post hospital year declines from approximately 10 per cent to 5 per cent during the second year. The rates of non-fatal recurrencies are similar. Mortality is related to age but not to the same extent to sex. Non-fatal recurrencies are, however, not related to age. Prediction of mortality is feasible by several prognostic models. Factors related to size of myocardial damage stand out as the important secondary risk factors for the years immediately after infarction. Most of these factors are not generally related to risk of non-fatal recurrencies. The proportion of cardiovascular deaths is 90 per cent during the first years and declines thereafter. Simplistically it may be said that the prognosis during the first years is related to the extent of the myocardial damage and thereafter primary risk factors become more important. Thus, it seems logical in the short-term perspective to influence myocardial factors and related arrhythmias and in the long-term perspective to influence primary risk factors which more likely operate on the vascular factors. Three preventive methods have demonstrated a positive benefit: 1) chronic beta-blockade, 2) cessation of smoking, 3) by-pass surgery in certain categories. After careful calculations it may be argued that at least half of the total mortality may be inhibited by beta-blockade and cessation of smoking. The impact of coronary surgery, lipid lowering and reduction of high blood pressures is more difficult to assess.

T wave changes after acute myocardial infarction predicting reinfarction

Of 420 consecutive patients with acute myocardial infarction who survived the coronary care unit period, 57 developed 63 reinfarctions with 16 deaths within three months (reinfarction group). Of the remaining 363 patients, 28 died without evidence of reinfarction during the same observation period and 335 survived. The last ECGs before discharge, or prior to a reinfarction in hospital, of the reinfarction patients were studied and compared with time-matched ECGs from the 335 survivors without reinfarction. In ECGs without interfering patterns, the slope of the ascending limb of a negative T wave was measured as the angle to the vertical plane (interobserver variation less than or equal to 5 degrees in 95%). Of the 63 reinfarctions, 40% had a steeply ascending limb of a negative T wave (T wave angle less than or equal to 55 degrees in lead II, less than or equal to 35 degrees in CR4 and/or less than or equal to 40 degrees in CR7) and a QRS complex without signs of infarction in the same lead (abnormal Q waves or abnormal R wave progression). The same criteria were fulfilled by 6% of the 335 survivors without reinfarction (p less than 0.001) and by one of the 28 patients who died without reinfarction. Thus, a steeply ascending limb of a negative T wave in the acute phase of a myocardial infarction heralds a reinfarction if the QRS complex of the same lead does not show signs of infarction (3-month sensitivity 40% and predictive value 53%). A T wave angle less than or equal to 35 degrees in CR4 corresponds to less than or equal to 40 degrees in V4. CR7 is not transferable to V6 but was the least predictive lead.

The postinfarction clinic in Göteborg, Sweden. A controlled trial of a therapeutic organization

Since Jan. 1, 1968, a Postmyocardial Infarction Clinic has been operating in Göteborg, Sweden. The methods used have been presented previously in this journal. The present study compares 96 male postinfarction cases, 57-67-year-old, treated at the Postmyocardial Infarction Clinic and a random sample of 85 patients not treated at the clinic. The mortality did not differ between the groups but there was a significant difference with regard to non-fatal reinfarction. The reasons for this are only partially explained by better control of accepted cardiovascular risk factors in the group treated at the clinic. Cessation of smoking was vigorously recommended but lipid lowering, antiarrhythmic or anticoagulant drugs were never used in this group. The results indicate that formalized management of homogeneous patient groups may achieve a general reduction of recurrences.

Detection of multivessel disease post myocardial infarction using an exercise-induced QRS score

OBJECTIVE

The aim of this study was to investigate the ability of Athens QRS score values to detect stenoses in other coronary arteries than the obstructed ones (which caused the myocardial infarction [MI]) in patients with a history of MI.

METHODS

We studied 125 patients (93 males and 32 females, mean age 54 +/- 7 years [range 45-68 years]) with a history of MI (46 patients with anterior MI, 54 patients with inferior MI, 25 patients with lateral MI). All patients underwent treadmill exercise testing and coronary arteriography.

RESULTS

Athens QRS score values were inversely related to the extent of CAD: -0.5 +/- 0.3 mm for patients with 1-VD (obstructed vessel), -3.4 +/- 2.2 mm for patients with 2-VD (obstructed vessel and stenosis in another vessel), and -5 +/- 1.8 mm for patients with 3-VD (obstructed vessel and stenoses in two more vessels). The ROC curves for the detection of multivessel disease showed that the area under the curve for QRS score values < -3 mm is significantly higher than the curve for ST-segment depression > or = 1 mm (0.948 vs 0.792, P < 0.001).

CONCLUSIONS

Values of the Athens QRS score less than -3 may distinguish single- from multivessel coronary artery disease in patients with a history of MI.

Acute coronary syndrome as a cause of sudden death in patients with old myocardial infarction: a pathological analysis

Old myocardial infarction (OMI) is one of the most important pathological manifestations in sudden cardiac death. Fatal arrhythmia arising from a fibrotic scar has been determined as the cause of death in most cases with old myocardial infarction. However, the significance of acute plaque disruption/thrombosis of the coronary arteries in those patients has not been investigated. We examined a series of 33 hearts from individuals with OMI who died suddenly during the period from 1998 to 2001. Detailed coronary pathological findings on these hearts indicated fresh or recent rupture of the coronary plaque with thrombosis in 18 cases (55%). As a result of comprehensive analysis, the sudden deaths were explained by acute coronary syndrome in 18 cases (55%), fatal arrhythmia in eight (24%), cardiac pump failure in five (14%), and other causes in two (6%) cases. Our findings revealed that a new coronary plaque rupture independent of the old infarct was a major cause of sudden cardiac death with OMI.

Effects of captopril on ischemic events after myocardial infarction. Results of the Survival and Ventricular Enlargement trial. SAVE Investigators

BACKGROUND

In the Survival and Ventricular Enlargement (SAVE) trial, recurrent myocardial infarction (MI) was the most important predictor of a poor outcome and conferred a sevenfold increase in risk of death. The purpose of this study was to determine the predictors of recurrent MI in study participants and to examine the influence of the angiotensin-converting enzyme inhibitor captopril on this and other myocardial ischemic events.

METHODS AND RESULTS

The 2231 patients had survived the acute phase of MI (3 to 16 days) and had a radionuclide ventricular ejection fraction < or = 40%. Patients were randomly assigned to receive double-blind treatment with either placebo or captopril and were followed for an average of 42 months. The influence of captopril on recurrent MI, cardiac revascularization procedures, and hospitalization with unstable angina was examined. The likelihood of recurrent MI was greater in patients with an MI or functional disability before the index infarction and higher systolic pressure (all P < .001) but was not influenced by baseline left ventricular ejection fraction. Therapy with captopril reduced the risk of development of recurrent MI by 25% (95% confidence intervals, 5% to 40%; P = .015) and the risk of death after recurrent MI by 32% (95% confidence intervals, 4% to 51%; P = .029). Captopril-assigned patients were also less likely to require cardiac revascularization procedures (P = .010), but hospitalization for unstable angina was unaltered. When all three of these major coronary ischemic events were considered together, captopril therapy reduced the risk (14% risk reduction; 95% confidence intervals, 0% to 26%; P = .047).

CONCLUSIONS

In post-MI patients with asymptomatic left ventricular dysfunction, long-term administration of captopril reduced recurrence of MI and the need for cardiac revascularization but had no influence on the rate of hospitalization with a discharge diagnosis of unstable angina. The finding that the recurrence of MI was independent of left ventricular ejection fraction suggests that captopril could be useful in preventing recurrent MI in patients with more preserved left ventricular function. The need for cardiac revascularization was reduced in patients receiving long-term captopril therapy, suggesting either an anti-ischemic effect or the ability of the angiotensin-converting enzyme inhibitor to modify the atherosclerotic process in survivors of MI.

Prevalence, characteristics and significance of ventricular premature complexes and ventricular tachycardia detected by 24-hour continuous electrocardiographic recording in the Cardiac Arrhythmia Suppression Trial. CAST Investigators

The prevalence, characteristics and significance of ventricular arrhythmias detected by ambulatory electrocardiography were evaluated in 1,498 patients who were randomized to encainide, flecainide or placebo in the Cardiac Arrhythmia Suppression Trial. The mean ventricular premature complex (VPC) frequency at baseline was 133 +/- 257 VPCs/hour. Nonsustained ventricular tachycardia (VT) (rate greater than or equal to 120 beats/min) was present in 22% of patients. Accelerated idioventricular rhythm (rate less than 120 beats/min) occurred in 22% of subjects. There were 63 deaths/resuscitated cardiac arrests in the active treatment (encainide/flecainide) group and 26 in the placebo group. In the treatment group mortality increased with increasing VPC frequency, (p = 0.006), whereas in the placebo group such a relation was not present. Mortality/resuscitated cardiac arrest increased in patients with greater than or equal to 2 VT episodes than in those with less than or equal to 1 episode in the active treatment group (p = 0.04). There was no significant association between VT and mortality/resuscitated cardiac arrest in the placebo group. The presence of accelerated idioventricular rhythm was not associated with increased mortality/resuscitated cardiac arrest in either the active treatment or placebo groups. However, mortality was lower in patients with accelerated idioventricular rhythm rates less than 100 beats/min than in those with rates greater than or equal to 100 beats/min (p = 0.05). Thus, in the Cardiac Arrhythmia Suppression Trial the previously described association between mortality/resuscitated cardiac arrest and ventricular arrhythmias (VPC and VT) were only observed in the active treatment group. In addition, based on the results obtained in this highly selected population, it is suggested that the definition of accelerated idioventricular rhythm should be a rate less than 100 beats/min, and at a rate greater than or equal to 100 beats/min it should be categorized as VT.

Did prognosis after acute myocardial infarction change during the past 30 years? A meta-analysis

Much effort has been spent to improve survival after acute myocardial infarction. To investigate how effective this effort has been, a meta-analysis was performed of studies published between 1960 and 1987 concerning mortality after acute myocardial infarction. Thirty-six studies were analyzed. They were classified with respect to deaths in the hospital and at 1 month and the 5-year mortality rate starting at hospital discharge. Mortality was assessed from all studies by comparing studies from different institutions with use of identical inclusion criteria (externally controlled studies) and by analyzing studies reporting on changes in mortality in two or more comparable patient cohorts admitted to the same institution at different time periods (internally controlled studies). Reports on clinical trials (for example, thrombolytic therapy, beta-adrenergic blockade) in acute myocardial infarction were excluded. Average overall in-hospital mortality decreased from 29% during the 1960s to 21% during the 1970s and to 16% during the 1980s. The externally controlled studies also showed a declining trend: from 1960 to 1969, 32%, from 1970 to 1979, 19% and from 1980 to 1987, 15%. The 1-month overall mortality rate decreased from 31% during the 1960s to 25% during the 1970s and 18% during the 1980s externally controlled studies. Most internally controlled studies also showed significant improvement in in-hospital and 1-month survival. In contrast, 5-year mortality after hospital discharge did not significantly decrease (33% from 1960 to 1969 and 33% from 1970 to 1979). It is concluded that in the prethrombolytic era, short-term prognosis after acute myocardial infarction has improved since 1960.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiographic subset analysis of diltiazem administration on long-term outcome after acute myocardial infarction. The Multicenter Diltiazem Post-Infarction Trial Research Group

The effect of diltiazem on long-term outcome after acute myocardial infarction (AMI) was assessed in 2,377 patients enrolled in the Multicenter Diltiazem Post-Infarction Trial and subsequently followed for 25 +/- 8 months. The study population included 855 patients (36%) with at least 1 prior AMI before the index infarction and 1,522 patients (64%) with a first AMI, of whom 409 (27%) had a first non-Q-wave AMI, 664 (44%) a first inferior Q-wave AMI, and 449 (30%) a first anterior Q-wave AMI. This post hoc analysis revealed that, among patients with first non-Q-wave and first inferior Q-wave AMI, there were fewer cardiac events during follow-up in the diltiazem than in the placebo group, and that the reverse was true for patients with first anterior Q-wave AMI or prior infarction. The diltiazem:placebo Cox hazard ratio (95% confidence limits) for the trial primary end point (cardiac death or nonfatal reinfarction, whichever occurred first) was: first non-Q-wave AMI-0.48 (0.26, 0.89); first inferior Q-wave AMI-0.66 (0.40, 1.09); first anterior Q-wave AMI-0.82 (0.51, 1.31); and prior AMI-1.11 (0.85, 1.44). Use of cardiac death alone as an end point gave an even more sharply focused treatment difference: first non-Q-wave AMI-0.46 (0.18, 1.21); first inferior Q-wave AMI-0.53 (0.27, 1.06); first anterior Q-wave AMI-1.28 (0.68, 2.40); prior infarction-1.26 (0.90, 1.77). Further analysis revealed that these differences in the effect of diltiazem in large part reflected the different status of the 4 electrocardiographically defined subsets in terms of left ventricular function.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic significance of nonfatal myocardial reinfarction. Multicenter Diltiazem Postinfarction Trial Research Group

In most risk stratification and intervention postinfarction trials, cardiac mortality is used as the major outcome end point either alone or in combination with nonfatal reinfarction. However, the independent risk carried by nonfatal reinfarction for subsequent cardiac death has not been quantified. The prognostic significance of nonfatal reinfarction was determined from the multicenter diltiazem trial data base of 1,234 patients treated with placebo followed up for 1 to 4 years after acute myocardial infarction. One hundred sixteen patients had at least one nonfatal reinfarction, 14 (12%) of whom subsequently experienced cardiac death. Of the remaining 1,118 patients without nonfatal reinfarction, 110 (9.8%) experienced cardiac death. Compared with event-free patients, patients with nonfatal reinfarction were more likely (p less than 0.05) to be women, to have had an infarction before their index event and to have had prior cardiac-related symptoms. Cox survivorship analyses, using pertinent baseline clinical variables along with nonfatal reinfarction as a time-dependent predictor variable, revealed that nonfatal reinfarction carried a significant and independent risk for subsequent cardiac mortality (hazard ratio 3.0, p = 0.002), which was greater than that carried by other significant predictor variables (New York Heart Association functional class, pulmonary congestion on chest radiograph, blood urea nitrogen level, predischarge Holter-recorded ventricular premature complexes and radionuclide ejection fraction). The cardiac mortality risk associated with nonfatal reinfarction was further increased in patients whose index event was their first infarction (hazard ratio 5.4, p = 0.0006). Thus, nonfatal reinfarction carries a strong, significant and independent risk for subsequent cardiac death in patients surviving an acute myocardial infarction.

The spectrum of death after myocardial infarction: a necropsy study

To determine the relative frequency of the causes of death in the acute (less than 24 hours), early (24 hours to 3 weeks), and chronic (greater than 3 weeks) phases of myocardial infarction, data from all autopsies performed at a university hospital during a 56-month period were reviewed. Autopsies were performed in 56% of in-hospital deaths and 27% of patients dead on arrival in the emergency room (out-of-hospital deaths). In 271 cases of suspected cardiac death, a myocardial infarction of any age was identified. Death had occurred in the acute phase of a first infarction in 19 patients and was most frequently due to pump failure (37%) followed by cardiac rupture (26%) and arrhythmias (21%). Death had occurred 24 hours to 3 weeks after a first infarction in 80 patients and was most frequently due to pump failure (44%), rupture (27%), and arrhythmias (16%). Recurrent acute infarction was found in 32% of patients whose deaths were due to arrhythmias or pump failure and in 19% of those whose deaths were due to rupture. Death had occurred greater than 3 weeks after a first infarction in 172 patients. In 132 (77%) of these patients death was due to a complication of a new acute or recent infarction. Myocardial rupture was a less frequent cause of death in patients with recurrent infarction (8%) than in those dying in the acute or early phase after their first infarction (27%, p = 0.0009). A primary arrhythmia in the absence of recurrent infarction or ischemia accounted for only 14% of out-of-hospital deaths late after an infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Characteristics associated with early (less than or equal to 3 months) versus late (greater than 3 months to less than or equal to 3 years) mortality after acute myocardial infarction

To define the independent variables predictive of early versus late mortality after acute myocardial infarction (AMI), 420 consecutive patients were studied and divided into 3 groups: the 45 patients who died within the initial 3 months (group 1), the 45 patients who died greater than 3 months and less than or equal to 3 years after AMI (group 2) and the 330 greater than 3-year survivors (group 3). The stepwise logistic discrimination method was applied to clinical and laboratory variables recorded during hospitalization to distinguish among the 3 groups. Six independent variables were found to be predictive of early mortality: left ventricular function score (chi-square 26.2; p less than 0.00001), ventricular fibrillation (chi-square 9.3; p = 0.002), bundle branch block (chi-square 9.0; p = 0.003), history of previous AMI (chi-square 8.7; p = 0.003), age (chi-square 5.8; p = 0.02) and atrioventricular block (chi-square 3.8; p = 0.05). Three independent variables were found predictive of late mortality: age (chi-square 13.8; p = 0.0002), anterior location of the AMI (chi-square 4.0; p = 0.04) and a low peak creatine kinase-MB level (chi-square 3.8; p = 0.05). Only 2 variables were able to distinguish between early and late nonsurvivors: peak creatine kinase-MB level (chi-square 8.7; p = 0.003) and ventricular fibrillation (chi-square 4.6; p = 0.03). Thus, the sets of independent risk factors for early and late mortality after AMI are substantially different--suggesting that differing mechanisms are responsible for outcome.

Mechanism of death and prevalence of myocardial ischemic symptoms in the terminal event after acute myocardial infarction

A prospective study to determine prognostic factors for risk stratification in 867 patients surviving the coronary care unit phase of acute myocardial infarction (AMI) is reported. During a 48-month follow-up, 144 patients (17%) died. The deaths were examined for the chronology, cause, mechanism, location and presence of myocardial ischemia in the terminal event. A classification previously proposed by Hinkle and Thaler was used to define the mechanism of cardiac death and the presence of ischemia. There were 113 deaths due to coronary atherosclerotic coronary artery disease, including 5 due to complications of coronary artery bypass graft surgery. Of the remaining 108 of these deaths, 74% were classified as due to an arrhythmic mechanism and 26% as myocardial failure. Of the deaths due to an arrhythmia or to myocardial failure, 56 (52%) occurred out of hospital. The ratio of arrhythmic: myocardial failure deaths was not different for the patients who died within 3 months after the index AMI compared with later deaths. Sudden death (less than or equal to 1 hour of new symptoms) was strongly associated with arrhythmic death but 32 (54%) of patients who died greater than 1 hour after the onset of symptoms were also classified as having an arrhythmic cause of death. Previously described risk factors, including an ejection fraction less than 0.40 and greater than or equal to 10 ventricular premature complexes/hour, were independent predictors of mortality but did not differentially predict the mechanism of cardiac death. Evidence of myocardial ischemia before the terminal event was found in about 50 (60%) patients whose deaths were witnessed and who died from an arrhythmia or myocardial failure.

The mortality risk associated with digitalis treatment after myocardial infarction

We examined the effects of digitalis therapy on postinfarction mortality throughout a 24-month to 48-month follow-up in 867 patients who survived an acute myocardial infarction. During follow-up, 145 patients died (16.7% mortality). At the time of hospital discharge, 31% of the patients were taking digitalis. The digitalis-treated patients were older, had more medical-cardiac risk factors, and had a higher mortality rate throughout the follow-up than the nondigitalis-treated patients. Statistical techniques were used to adjust for clinical imbalances between the digitalis-treated patients and nondigitalis-treated patients. The survival analysis (n = 728 patients) utilized the Cox regression model, and the digitalis-associated mortality risk was identified only after all significant covariates were allowed, so that mortality could be predicted as accurately as possible. Digitalis therapy was associated with a significantly increased postinfarction mortality risk after adjustment for the predictor covariates (relative risk 2.3, 95% confidence interval 1.4-3.7, p less than 0.001). The findings from this large multicenter study suggest that it would be prudent to exercise caution in the use of digitalis in postinfarction patients.

A new electrocardiographic classification for post-myocardial infarction clinical trials

A new electrocardiographic code was developed for clinical trials involving patients with acute myocardial infarction (AMI). In the Multicenter Post-Infarction Program (MPIP), the electrocardiogram, classified by the Minnesota code, was not useful as a clinical predictor and played almost no role in subsequent analysis. To test its value the new code was applied to the electrocardiograms of 653 of the 866 patients in the MPIP data base who had sustained a first AMI. The MPIP code identifies AMI by region and severity. The 4 regions are anterior, lateral, inferior and posterior, defined by traditional criteria. Severity codes include Q-wave and non-Q-wave AMI, ST depression and no ischemic changes. The interpretation for each of 4 regions results in a 4-digit location severity code that is amenable to sorting and analysis. Fourteen separate and mutually exclusive groups were identified. Mortality gradients were found within the inferior AMI groups, but not within the anterior AMI groups. Mean ejection fraction was 50% for patients with isolated anterior infarction and decreased progressively (p less than 0.0003) as the extent of lateral wall involvement increased. For isolated inferior AMI, mean ejection fraction was 53%; lateral or posterior involvement did not significantly change this. The MPIP code is easy to apply, correlates acceptably well with clinically relevant variables of left ventricular function and permits the electrocardiogram to be used as a clinical predictor in large clinical trials.

Long-term prognosis of patients with acute myocardial infarction: is mortality and morbidity as low as the incidence of ischemic heart disease in Japan

Long-term prognosis of hospital survivors with myocardial infarction (MI) was investigated to assess the validity of previous reports on the low incidence of ischemic heart disease in Japan. Among 686 patients with acute MI, 115 (16.8%) died during hospitalization and eight were lost to follow-up. The cumulative mortality rate of the 563 hospital survivors was 6.2% in the first year, 12.0% in the third year, and 19.1% in the fifth year, with cardiac death accounting for 63% of the deaths. Cumulative rates for recurrent MI were 4.4% in the first year, 11.0% in the third year, and 13.2% in the fifth year. Parameters influencing long-term mortality rates obtained by stepwise discriminant analysis were arteriosclerosis-related factors, presence of congestive heart failure at admission, age, and presence of previous MI, while parameters influencing the recurrence of MI were congestive heart failure, arteriosclerosis-related factors, and ischemic findings at discharge. Our findings indicate that the prognosis for patients with MI is far better in Japan than in Western countries and support the previous reports on the low incidence of ischemic heart disease in Japan, while factors influencing the prognosis are similar to those previously reported.

Myocardial infarction in young patients: an analysis by age subsets

We examined, in age subsets, 2643 patients with acute myocardial infarction. Clinical features and 1 year morbidity and mortality were compared in 203 young patients (less than 45 years), 1671 patients 46 to 70 years old, and 769 elderly patients (greater than 70 years). Ninety-two percent of young patients were men, and a family history of premature coronary artery disease was more common in young patients (41% compared with 28% of middle-aged and 12% of elderly patients). More young patients were currently smoking cigarettes (82% compared with 56% of middle-aged and 24% of elderly patients), and only 8% of young patients had never smoked. Previous myocardial infarction and history of angina pectoris or congestive heart failure were less common (p less than .001) in the young patients than in middle-aged and elderly patients. In-hospital mortality was only 2.5% for young patients, compared with 9.0% in middle-aged and 21.4% in elderly patients (both p less than .001). Postdischarge 1 year mortality was also strikingly low in young patients, at 2.6% compared with 10.3% in middle-aged and 24.4% in elderly patients. The incidence of reinfarction during the 1 year of follow-up was similar in all subsets. The statistical significance of 65 variables as predictors of 1 year mortality and reinfarction was tested and the following found to be significant (p less than .05): hospital discharge on antiarrhythmic drugs, digoxin, or diuretics; history of previous myocardial infarction or congestive heart failure; chest x-ray findings of heart failure; low ejection fraction; and atrial fibrillation. Thus, young patients entering the hospital have an excellent 1 year prognosis, but those with prior infarction in whom there are selected abnormal findings at hospital discharge comprise a subgroup that may benefit from early aggressive management.

Coronary angiography and pathogenesis of coronary artery disease in young male survivors of myocardial infarction

Coronary angiography was performed 3 to 6 months after myocardial infarction in 107 males below the age of 45 (mean age 39.7 +/- 3.9, range 23-44 years). The coronary angiograms were allocated to various groups according to the presence or absence of obvious atheromatous changes. Metabolic evaluation included determination of cholesterol and triglyceride concentrations in the major serum lipoproteins. Marked elevation of low density lipoprotein (LDL) cholesterol concentration was found in patients with angiographic evidence of atheromatosis, in contrast to patients with normal coronary angiograms or with single occlusion and no other abnormalities. Thus, there was a correlation between angiographic appearance of the coronary arteries and disturbances of LDL metabolism. It is proposed that coronary angiography may distinguish between atheromatous and non-atheromatous pathogenesis of myocardial infarction at young age.

Nonfatal cardiac events and recurrent infarction in the year after acute myocardial infarction

The occurrence and importance of nonfatal cardiac events in the year after an acute myocardial infarction were studied in 866 patients who were enrolled by nine hospitals with a broad geographic distribution. The extensive clinical data acquired on each patient included special tests, such as radionuclide-determined ejection fraction, 24 hour ambulatory electrocardiogram and a low level exercise tolerance test. Recurrent events were frequent in the first 5 months, and certain events were significant indicators of a poor prognosis. An ejection fraction less than 40% and angina after discharge from the coronary care unit predicted patients at high risk of rehospitalization. Recurrent infarction was similarly predicted by angina, but not by any features of an exercise test. This study demonstrates the considerable morbidity that occurs after an acute myocardial infarction and its relation to and role in subsequent mortality.

Declining trend in mortality after myocardial infarction

All patients under 60 years of age who were discharged from hospital after a first myocardial infarction between 1968 and 1977 in Göteborg were followed for a minimum of 24 months. The patients were unselected, and treatment was standardised. The patients were divided into five two yearly cohorts, and the prognostic comparability and mortality of these cohorts were assessed. There was a reduction in the two year mortality rate after discharge during the 10 year period. Small baseline differences between the cohorts were controlled by multivariate methods, and a subsequent analysis showed that there was a declining trend in mortality between 1968 and 1977. A higher tendency among smokers to give up smoking and a lower prevalence of angina pectoris could explain only part of the reduction in mortality. A small number of patients underwent a coronary bypass operation; the slight increase in the number of operations during the period cannot, however, account for the reduced mortality. Most of the patients in the later cohorts were treated with beta blockers, and this is the most likely explanation for the majority of the decline in mortality.

Risk stratification and survival after myocardial infarction

We assessed the role of physiologic measurements of heart function in predicting mortality after myocardial infarction. Most of the 866 patients enrolled in our multicenter study underwent 24-hour Holter monitoring and determination of the resting radionuclide ventricular ejection fraction before discharge. Univariate analyses showed a progressive increase in cardiac mortality during one year as the ejection fraction fell below 0.40 and as the number of ventricular ectopic depolarizations exceeded one per hour. Only four risk factors among eight prespecified variables were independent predictors of mortality: an ejection fraction below 0.40, ventricular ectopy of 10 or more depolarizations per hour, advanced New York Heart Association functional class before infarction, and rales heard in the upper two thirds of the lung fields while the patient was in the coronary-care unit. Various combinations of these four factors identified five risk subgroups with two-year mortality rates ranging from 3 per cent (no factors) to 60 per cent (all four factors).

Periods of differing mortality distribution during the first year after acute myocardial infarction

The mortality rate after acute myocardial infarction (AMI) has generally been modeled by a single exponential function. The present study was undertaken to determine, in 3 different populations, whether or not periods exist during the first year after AMI which have mortality distributions that differ from this pattern. The 3 patient populations included San Diego (346 patients, 71 deaths), Vancouver (704 patients, 146 deaths), and Copenhagen (1,140 patients, 262 deaths). Hospital admission was within 24 hours of the onset of symptoms, and patients dying within the first 24 hours after hospital admission or of noncardiac or unknown causes were not analyzed. The mortality between 2 and 21 days in the combined data base was 11.4% (range 10.9 to 11.7) and from 3 weeks to 1 year 10.5% (range 9.0 to 11.3). A high degree of similarity was noted among the shapes of the 3 survival curves. The hypothesis of an exponential mortality rate during the entire first year was rejected. Using a special statistic, changepoints at days 17, 23, and 24 in the 3 populations (21 days for the combined data base) were identified and used thereafter to divide the year into 2 separate periods of mortality within which exponentiality for the mortality rate was not rejected. The point by which exactly 50% of deaths had occurred was day 19, with 75% of deaths occurring by day 100. These data further define the natural history after AMI and indicate optimal follow-up periods for short- and longer-term management strategies based on risk assessment or trials of risk reduction after AMI.

Cessation of smoking after myocardial infarction. Effects on mortality after 10 years

Ten annual cohorts of men suffering from their first myocardial infarction have been followed up to a maximum period of 10.5 years. One thousand and twenty-three male patients of 1306 were smokers. Three months after the infarction 55% had stopped smoking and 45% continued smoking. These two groups were then compared and followed with regard to non-fatal reinfarctions and deaths. Preinfarction characteristics were shown to be similar for the two groups. The prognostic comparability of the two groups was tested using two multiple logistic models. Those who stopped smoking had a slightly higher predicted two year mortality after the infarction. In different age groups it is shown with life table technique that those who stopped smoking had a considerably higher survival rate and lower cumulative frequency of reinfarction. The present study shows a reversion of the expected prognosis after myocardial infarction caused by changing the smoking habit.

The chronology and suddenness of cardiac death after myocardial infarction

A prospective postinfarction study of 978 patients less tha 66 years of age followed from 1 to 5 years was utilized to evaluate the chronology (interval from hospital discharge to demise) and suddenness (elapsed time from the onset of terminal symptoms to demise) of cardiac death. Clinical information including the patient's history and CCU, 6-hour Holter electrocardiographic, medication, and mortality event data was available on 112 cardiac deaths, with 56% of those with witness deaths dying suddenly (less than or equal to 1 hour). During the first postinfarction year 50% of the nonsudden deaths occurred within the first month after hospital discharge, whereas 84% of the sudden deaths occurred in the 2 to 12 month period after infarction (Chi Square = 6.25, p less than 0.02). There were no clinical variables including Holter-recorded ventricular premature beats that distinguished between early and late or sudden and nonsudden cardiac death. These findings indicate that the chronology and suddenness of the terminal cardiac event are more difficult to predict than had previously been appreciated. The therapeutic implications of these observations are discussed.

Timolol-induced reduction in mortality and reinfarction in patients surviving acute myocardial infarction

A multicenter double-blind randomized study was carried out to compare the effect of timolol (10 mg twice daily) with that of placebo in patients surviving acute myocardial infarction. Treatment was started seven to 28 days after infarction in 1884 patients (945 taking timolol, and 939 placebo), who represented 52 per cent of those evaluated for entry; the patients were followed for 12 to 33 months (mean, 17). There were 152 deaths in the placebo group and 98 in the timolol group. When deaths that occurred during treatment or within 28 days of withdrawal were considered, the cumulated sudden-death rate over 33 months was 13.9 per cent in the placebo group and 7.7 per cent in the timolol group--a reduction of 44.6 per cent (P = 0.0001). The cumulated reinfarction rate was 20.1 per cent in the placebo group and 14.4 per cent in the timolol group (P = 0.0006). We conclude that long-term treatment with timolol in patients surviving acute myocardial infarction reduces mortality and the rate of reinfarction.

Five-year survival of 728 patients after myocardial infarction. A community study

This study deals with the five-year survival of 728 myocardial infarction patients who survived the first 28 days after the onset of symptoms. The series was collected by the Helsinki Coronary Register and includes all cases of acute myocardial infarction in the population who were under 66 years of age during the period 1 July 1970 to 30 June 1971. Of the 219 patients who subsequently died, 81.8 per cent died from ischaemic heart disease. The mortality was highest during the first year after the acute phase but did not decrease after the second year. The mortality was higher in patients with a transmural infarction (five-year mortality 34.0%) compared with those with a nontransmural infarction (19.7%). The mortality also was higher for recurrent acute myocardial infractions than for first attacks. The five-year mortality for women was less (20.5%, age-adjusted) than for men (31.6%). This is mainly because of the higher incidence of nontransmural infarcts in women. Acute ischaemic heart disease is more common, more often fatal, and has a poorer long-term prognosis in men than in women in Helsinki. The acute mortality from acute ischaemic heart disease is high in Helsinki when compared with other WHO registers and, in addition, the long-term prognosis seems to be relatively poor in Helsinki.

Cardiovascular complications during exercise training of cardiac patients

The occurrence of major cardiovascular complications during exercise training of cardiac patients in 30 cardiac rehabilitation programs in North America was determined by questionnaire. These programs conducted medically supervised cardiac exercise classes in 103 locations and reported information on 13,570 participants who accumulated a total of 1,629,634 patient hours of supervised exercise. Cardiovascular complications were reported as nonfatal or fatal and included cardiac arrest, myocardial infarction and other. A total of 50 cardiac arrests were observed during exercise, 42 of which were successfully resuscitated while eight were fatal. Seven myocardial infarctions were reported; five were nonfatal and two were fatal. Four other fatalities were reported due to acute cardiopulmonary disorders. The average complication rate for all programs was one nonfatal and one fatal event every 34,673 and 116,402 patient hours of participation, respectively. Complication rates are lower in programs which continuously monitor the electrocardiogram during exercise and are lower when only the experience since 1970 is evaluated. These data support the recommendation that medically prescribed and supervised exercise can be performed reasonably safely by medically selected cardiac patients.

Cerebrovascular incidents after myocardial infarction

Pathological studies show a high correlation between the degree of atheroma in coronary, cerebral, and carotid arteries. Necropsy evidence of myocardial infarction also shows a high prevalence of severe atheroma in the carotid arteries. A further pathological finding is that obstruction in cerebral and carotid circulations is commonly due to embolism from the heart. In contrast, long-term follow-up of survivors of myocardial infarction indicates a low prevalence of cerebrovascular disease. To test if this low prevalence is due to lack of clinical ascertainment, a study was made of 260 survivors of myocardial infarction followed for five years. Specific attention was given to eliciting any clinical manifestations of cerebrovascular disease. In this study it was confirmed that in survivors of myocardial infarction the prevalence of cerebrovascular disease is surprisingly low: completed strokes 4%, transient cerebral ischaemic attacks 2%. A possible explanation of the low prevalence is that after the acute episode of myocardial infarction attacks of cardiac dysrhythmia predisposing to systemic embolism become infrequent.

Cardiac Death in the first 6 months after myocardial infarction: potential for mortality reduction in the early posthospital period

In a prospective postmyocardial infarction study of 759 patients aged less than 66 years, 42 posthospital cardiac deaths (42 of 759; 6 percent) occurred during a 6 month follow-up period. The average age of those who died was 53.5 +/- 8.8 (+/- standard error) years, and postmortem examination was obtainedon 36 percent. Almost 60 percent of the 6 month posthospital mortality occurred within 2 months after hospital discharge. Fifty-five percent of the cardiac deaths occurred either outside th ehospital or within hospital emergency departments, and 62 percent of the deaths were sudden (within 12 hours) or unwitnessed. The suspected mechanism of cardiac death was a primary arrhythmia in 62 percent, and a definite or probable myocardial infarction was diagnosed in only 41 percent. Use of digitalis and diuretic and antiarrhythmic agents was significantly (P is less than 0.025) greater in this group during the week before death than in a comparison survivor group; no difference in use of propranolol or tranquilizers was noted between the two groups. Fifty percent of the group that died had two or more of the following factors: death outside the hospital, sudden death, primary arrhythmic death. These findings indicate that a considerable potential exists for reducing cardiac death in the early posthospital phase of myocardial infarction.