Prognosis of early versus late ventricular fibrillation complicating acute myocardial infarction.

Earlier studies have suggested that patients exhibiting late (> 24 h) ventricular fibrillation during acute myocardial infarction had a poorer outcome in comparison to myocardial infarction patients with early (< 24 h) ventricular fibrillation. Between August 1981 and July 1983, 5839 consecutive patients with acute myocardial infarction were hospitalized in 13 out of 21 operating coronary care units in Israel. Demographic and medical data were collected from hospitalization charts and during 1 year of follow-up. Mortality assessment was done for 99% of hospital survivors up to mid-1988 (mean, 5.5 years). The incidence of ventricular fibrillation in the SPRINT Registry was 6% (371/5839). Patients with ventricular fibrillation in the setting of cardiogenic shock (n = 107) were excluded from analysis. Patients with late ventricular fibrillation (n = 109; 41%) were older and had a more complicated hospital course than patients with early ventricular fibrillation (n = 155; 59%). In-hospital and 1-year post-discharge mortality were significantly higher in patients with late ventricular fibrillation (63% and 17%) as compared to patients with early ventricular fibrillation (26% and 4%, respectively; P < 0.05 for each). This difference vanished 5 years after hospital discharge. After multiple logistic regression analysis late occurrence of ventricular fibrillation emerged as an independent predictor of increased in-hospital mortality (Odds ratio, 4.29; 95% confidence interval, 2.11-8.74) but not for subsequent death. Patients with late ventricular fibrillation during the hospital course of acute myocardial infarction had a poorer immediate and subsequent outcome in comparison to patients with early ventricular fibrillation.

Frequency and prognostic significance of secondary ventricular fibrillation complicating acute myocardial infarction. SPRINT Study Group.

The incidence of secondary ventricular fibrillation (VF) complicating acute myocardial infarction (AMI) was 2.4% in a large cohort of unselected patients with AMI (142 of 5,839). Secondary VF was more frequent in patients with recurrent AMI (4%) than in those with a first AMI (1.9%) (p < 0.01). The hospital course was more complicated and in-hospital mortality was significantly higher in patients with secondary VF than in those with the same clinical hemodynamic condition but without VF (56 vs 16%; p < 0.0001). Multivariate analyses confirmed secondary VF complicating AMI as an independent predictor of high in-hospital mortality, with an odds ratio of 7 (95% confidence interval 4.6-10.6). However, long-term mortality after discharge (mean follow-up 5.5 years) was not increased in patients with as compared with those without secondary VF (39 vs 42%). These findings were also true when patients receiving beta blockers and antiarrhythmic therapy were excluded from analysis. Thus, this life-threatening arrhythmia occurring during hospitalization is not a marker of recurrent susceptibility to VF or an indicator of increased mortality after discharge from the hospital.

The prognostic significance of angina pectoris preceding the occurrence of a first acute myocardial infarction in 4166 consecutive hospitalized patients.

We examined the role of chronic (greater than 1 month) angina pectoris (AP) before acute myocardial infarction (AMI) in predicting hospital and long-term mortality rates among 4166 patients with first AMIs. The prevalence of AP in these patients was 43%. Chronic AP was more common in women (49%), patients with hypertension (49%), and diabetic patients (49%) than in men and counterparts free of the former conditions (p less than 0.005). In patients with AP the hospital course was more complicated and non-Q-wave AMI was more common than in counterparts without AP. In-hospital (16%), as well as 1 (8%)- and 5-year postdischarge (26%), mortality rates in hospital survivors were higher among patients with previous AP than in patients without previous AP (12%, 6%, and 19%, respectively) (p less than 0.01). After adjustment for age and all other predictors of increased hospital mortality rates in this cohort of patients, AP preceding AMI emerged as an independent predictor of increased hospital mortality rates (odds ratio 1.30; 90% confidence interval 1.10 to 1.53). For postdischarge mortality rates (mean follow-up 5 1/2 years), the covariate-adjusted relative risk of death in patients with AP was similar at 1.29 (p less than 0.0001; 90% confidence interval 1.16 to 1.44), according to estimation by Cox proportional hazards model. These data support the notion that preexisting AP identifies a group of patients at increased risk of death.

Long-term prognosis after acute myocardial infarction in patients with left ventricular hypertrophy on the electrocardiogram. SPRINT Study Group.

Among 4,720 consecutive hospital survivors from acute myocardial infarction (AMI) treated in 13 coronary care units between July 1981 and August 1983, the estimated prevalence of electrocardiographic left ventricular (LV) hypertrophy was 6.1%. The prevalence of electrocardiographic LV hypertrophy increased with age and was higher in patients with previous myocardial infarction, angina and systemic hypertension. Mean age of patients with electrocardiographic LV hypertrophy was 67.2 vs 61.4 years in counterparts free of electrocardiographic LV hypertrophy. Patients with electrocardiographic LV hypertrophy had a higher rate of congestive heart failure on admission, or developing during their stay in coronary care units. The 1- and 5-year mortality rates were 19.7 and 46.6% among patients with electrocardiographic LV hypertrophy versus 8.7 and 26.2%, respectively (p less than 0.001) in patients without this finding. The covariate-adjusted odds ratio of 1-year mortality was 1.88 for the presence of electrocardiographic LV hypertrophy when age alone was adjusted for, and 1.51 (90% confidence interval, 1.09 to 2.10) when multiple covariate adjustment was undertaken. After multiple covariate adjustment for 5-year mortality after discharge, the relative risk associated with electrocardiographic LV hypertrophy was 1.51 (90% confidence interval, 1.26 to 1.80). The results of the present study showed that the presence of electrocardiographic LV hypertrophy on the discharge electrocardiogram of survivors from AMI is associated with a 1.5-fold increase of short- and long-term mortality. Patients with electrocardiographic LV hypertrophy, potentially at an increased post-discharge risk, may be candidates for early noninvasive testing and more intensive follow-up after recovering from AMI.

Cerebrovascular accident complicating acute myocardial infarction: incidence, clinical significance and short- and long-term mortality rates. The SPRINT Study Group.

PURPOSE: The purpose of this study was to report the incidence, the antecedents, and the clinical significance of clinically recognized cerebrovascular accidents or transient ischemic attacks (CVA-TIA) complicating acute myocardial infarction. PATIENTS AND METHODS: During 1981 to 1983, a secondary prevention study with nifedipine (SPRINT) was conducted in 14 hospitals in Israel among 2,276 survivors of acute myocardial infarction. During the study, demographic, historical, and medical data were collected on special forms for all patients with diagnosed acute myocardial infarction in 13 of these 14 hospitals (the SPRINT registry, n = 5,839). Mortality follow-up was completed for 99% of hospital survivors for a mean follow-up of 5.5 years (range: 4.5 to 7 years). RESULTS: The incidence of CVA-TIA was 0.9% (54 of 5,839). The latter rate increased significantly only with age, from 0.4% among patients up to 59 years old to 1.6% among those aged greater than or equal to 70 years. Multivariate analysis identified age, congestive heart failure, and history of stroke as predictors of CVA-TIA during the acute phase of myocardial infarction. Patients with CVA-TIA exhibited a complicated hospital course, with a 15-day mortality rate of 41%. Subsequent mortality rates in survivors at 1 and 5 years were 34% and 59%, respectively. Rates at the same time points in patients without CVA-TIA were 16%, 11%, and 29% (p less than 0.01). In a multivariate analysis that included age, gender, congestive heart failure, history of previous myocardial infarction, and hypertension, CVA-TIA was independently associated with increased 15-day mortality (covariate-adjusted odds ratio [OR] = 2.62; 90% confidence interval [CI], 1.59 to 4.32), as well as subsequent 1-year (OR = 3.29; 90% CI, 1.70 to 6.36) and long-term (mean follow-up = 5.5 years) mortality (OR = 2.46; 90% CI, 1.30 to 4.69). CONCLUSION: In this large cohort of consecutive patients with myocardial infarction, CVA-TIA was a relatively infrequent complication of acute myocardial infarction. Factors independently favoring the occurrence of CVA-TIA were old age, previous CVA, and congestive heart failure. CVA-TIA occurring during acute myocardial infarction independently increased the risk of early death threefold as well as the risk of long-term mortality in early-phase survivors. (2.5-fold).

Q-T prolongation and polymorphous ("torsade de pointes") ventricular arrhythmias associated with organophosphorus insecticide poisoning.

It is not generally appreciated in the Western world that organophosphorus poisoning may be associated with a serious and often fatal cardiac complication: Q-T interval prolongation with malignant ventricular arrhythmias of the "torsade de pointes" type. This insidious complication may lead to delayed, sudden death after the patients appears to be well on the way to recovery from the other, more dramatic respiratory and neurologic symptoms. In this study 15 patients with organophosphorus poisoning are described. Q-T prolongation was observed in 14 and malignant tachyarrhythmias in 6. In view of the dismal prognosis of these patients, ventricular pacing, previously used with success in other conditions associated with this syndrome, was tried in four patients and successfully shortened the Q-T interval and eliminated the arrhythmias. Isoproterenol did the same in a fifth patient. Awareness of this lethal, but preventable complication of organophosphorus poisoning is called for. Careful electrocardiographic monitoring is necessary until the Q-T interval returns to normal. Electrical pacing appears to be the treatment of choice for the tachyarrhythmias.