Prognostic implications of ventricular ectopy one week, one month, and sixteen months after an acute myocardial infarction. Danish Study Group on Verapamil in Myocardial Infarction

BACKGROUND

Ventricular ectopy early after an acute myocardial infarction (AMI) has previously been demonstrated to predict mortality. Less information is available about the prognostic implications of ventricular ectopy occurring late after an AMI, and no information is available about the prognostic implication of the development of ventricular ectopy during the first year after an AMI.

HYPOTHESIS

The purpose of the present prospectively conducted trial, a part of the Danish Verapamil Infarction Trial II (DAVIT II), was to evaluate the prognostic implication of (1) ventricular premature complexes (VPCs) recorded by 24-h Holter monitoring 1 week, 1 month, and 16 months after an AMI; and (2) development of > 10 VPCs/h or of any complex ventricular ectopy, that is, pairs, more than two types of VPCs, ventricular tachycardia, or > 10 VPCs/h during follow-up after an AMI.

METHODS

Patients were monitored 1 week (n = 250), 1 month (n = 210), and 16 months (n = 201) after AMI.

RESULTS

Multivariate analyses based on history, clinical findings, and ventricular ectopy showed the following results: After 1 week, > 10 VPCs/h (p = 0.0006) and heart failure (p < 0.007); after 1 month, > 10 VPCs/h (p = 0.003) and resting heart rate (p < 0.02); and after 16 months, ventricular tachycardia (p = 0.002) independently predicted long-term mortality. Mortality was significantly predicted by the development of > 10 VPCs/h from 1 week to 1 month (p = 0.003) and 16 months (p = 0.03), and from 1 to 16 months (p = 0.007) after AMI, as well as by the development of any complex ventricular ectopy from 1 week to 1 month (p = 0.02) and 16 months (p = 0.01), and from 1 to 16 months (p = 0.04) after AMI.

CONCLUSION

The present study demonstrated that 1 week and 1 month after an AMI the quantity of VPCs, that is, > 10 VPCs/h, predicted mortality, whereas 16 months after an AMI the quality of VPCs, that is, ventricular tachycardia, predicted mortality.

Treatment with verapamil and trandolapril in patients with congestive heart failure and angina pectoris or myocardial infarction. The DAVIT Study Group. Danish Verapamil Infarction Trial

In a double-blind, randomized trial in a consecutive group of postinfarct patients in treatment with diuretic agents for congestive heart failure, the 3 month rate of cardiac events (i.e., death, repeat infarction, unstable angina pectoris, or repeat admission because of heart failure) was 14% in patients treated with verapamil and trandolapril and 35% in patients treated with trandolapril (p = 0.01). In another study of patients with angina pectoris and left ventricular ejection fraction less than 40%, trandolapril plus verapamil improved exercise duration and left ventricular ejection fraction. These findings indicate that combined treatment with verapamil and trandolapril may be beneficial in patients with congestive heart failure.

Cardiac event rates after acute myocardial infarction in patients treated with verapamil and trandolapril versus trandolapril alone. Danish Verapamil Infarction Trial (DAVIT) Study Group

Angiotensin-converting enzyme (ACE) inhibitors improve survival in patients with congestive heart failure (CHF) after an acute myocardial infarction (AMI), but mortality may be as high as 10% to 15% after 1 year. Verapamil prevents cardiac events after an AMI in patients without CHF. We hypothesized that in postinfarct patients with CHF already prescribed diuretics and an ACE inhibitor, additional treatment with verapamil may reduce cardiac event rate. In this multicenter, double-blind study, patients with CHF receiving diuretic treatment were consecutively randomized to treatment with trandolapril 1 mg/day for 1 month and 2 mg/day the following 2 months (n = 49), or to trandolapril as mentioned plus verapamil 240 mg/day for 1 month and 360 mg/day for 2 months (n = 51). Trial medication started 3 to 10 days after AMI. All patients were followed for 3 months. End points in the trandolapril/trandolapril-verapamil groups were death 1/1, reinfarction 7/1, unstable angina 9/3, and readmission for CHF 6/2. The 3-month first cardiac event rate was 35% in trandolapril-treated patients and 14% in trandolapril-verapamil-treated patients (hazard ratio 0.35, 95% confidence interval 0.15 to 0.85, p = 0.015). These data suggest that verapamil reduces cardiac event rates in post-AMI patients with CHF when added to an ACE inhibitor and a diuretic.

Treatment with verapamil and trandolapril in patients with congestive heart failure and myocardial infarction. The Danish Verapamil Infarction Trial (DAVIT Study Group)

EFFECTS OF VERAPAMIL AND TRANDOLAPRIL: Progression of heart failure, sudden death and death from re-infarction are the major cause of the increased mortality in postinfarct patients with congestive heart failure. Angiotensin converting enzyme (ACE) inhibitors such as trandolapril can prevent the progression of heart failure and thus improve survival. The calcium antagonist verapamil has been shown to prevent sudden death and re-infarction in postinfarct patients without congestive heart failure.

HYPOTHESIS

The Danish Verapamil Infarction Trial (DAVIT) study group hypothesized the combined treatment with trandolapril and verapamil might prevent cardiac events in postinfarct patients with coronary heart disease. The first double-blind randomized trial included 100 patients and supported this hypothesis, as the cardiac event rate was significantly lower after 3 months in patients treated with the combination than in those treated with trandolapril alone (14 versus 35%, respectively; P = 0.01, hazard ratio 0.35, 95% confidence interval 0.15-0.85).

The diagnoses of patients admitted with acute chest pain but without myocardial infarction

OBJECTIVE

The purpose of this study was to describe the frequencies of various diagnoses in patients admitted with acute chest pain, but without acute myocardial infarction, and to evaluate a non-invasive screening programme for these patients.

PATIENTS

A total of 204 consecutive non-acute myocardial infarction patients were included. Fifty-six had a definite diagnosis within 48 h, whereas 148 patients underwent an examination programme including pulmonary scintigraphy, echocardiography, exercise electrocardiography, myocardial scintigraphy, Holter monitoring, hyperventilation test, oesophago-gastro-duodenoscopy, 3 h monitoring of oesophageal pH, oesophageal manometry, Bernstein test, physical examination of the chest wall and thoracic spine, bronchial histamine provocation test and ultrasonic examination of the abdomen.

RESULTS

According to predefined criteria, 186 patients (91%) had at least one diagnosis, 144 had one, whereas 39 had two, and three patients had three diagnoses. In 18 patients no diagnosis was obtained. The diagnoses belonged mainly to three groups: (1) ischaemic heart disease (n = 64); (2) gastro-oesophageal diseases (n = 85); (3) chest-wall syndromes (n = 58). Less frequent diagnoses included pulmonary embolism, pleuritis/pneumonia, lung cancer, aortic stenosis, aortic aneurysm and herpes zoster.

CONCLUSIONS

The high risk subset of a non-acute myocardial infarction population can be identified by means of a clinical evaluation and non-invasive cardiac examinations. Among the remainder, pulmonary embolism, gastro-oesophageal diseases and chest-wall syndromes should be paid special attention. A careful physical examination of the chest wall and upper endoscopy seems to be the most cost-beneficial examination to employ in this subset.

Effect of verapamil on the prognosis of patients with early postinfarction electrical or mechanical complications. The Danish Verapamil Infarction Trial II (DAVIT II)

The Danish Verapamil Infarction Trial II (DAVIT II) demonstrated from the second postinfarction week, that long term treatment with verapamil significantly improved reinfarction free survival after an acute myocardial infarction (AMI). The present post hoc analysis of DAVIT II was undertaken with the purpose of evaluating the effect of treatment with verapamil in patients with early electrical complications, i.e. ventricular or atrial fibrillation, ventricular tachycardia, or second or third degree atrioventricular block, with or without mechanical complication, i.e. heart failure, during the first post-AMI week. In the placebo group, the 18-month mortality rate was lowest (9.5%) in patients without electrical or mechanical complications, highest (24.6%) in patients with electrical events only, and in-between (17.5%) in patients with mechanical problems regardless of presence of electrical complications. Verapamil significantly reduced the 18-month mortality rate in patients with early electrical without mechanical complications (60% reduction, P = 0.02), and in patients without mechanical complications (35% reduction, P = 0.02). Verapamil did not change the mortality rate in patients with mechanical complications.

Short- and long-term prognostic implications of in-hospital postinfarction arrhythmias. DAVIT II Study Group

The purpose of the present study was to evaluate, in patients surviving the first postinfarction week, the short- and long-term prognostic implications of arrhythmias, and their relation to easily obtained anamnestic and clinical parameters presented during hospitalisation. The study consisted of 897 placebo-treated patients of the Danish Verapamil Infarction Trial II (DAVIT II). In patients with and without supraventricular tachycardia mortality within 2 months was 9.2 and 3.7% (p = 0.004), respectively. By multivariate analysis supraventricular tachycardia independently predicted mortality within 2 months. Mortality within 5 years was predicted by the presence of supraventricular tachycardia, atrial fibrillation, advanced atrioventricular block, sinoatrial block, and of the combined arrhythmic parameter, i.e. ventricular and/or atrial fibrillation and/or advanced atrioventricular block. When easily obtained and assessed anamnestic and clinical parameters were included in a multivariate analysis, the presence of supraventricular tachycardia alone gave independent prognostic information on long-term mortality.

Effect of verapamil on arrhythmias and heart rate during 16 months following an acute myocardial infarction. The Danish Study Group on Verapamil in Myocardial Infarction

The present study was a prospectively planned subset of the postinfarction, double blind, randomized, multicenter, placebo controlled trial of verapamil, DAVIT II. Patients had 24 hours of Holter monitoring before randomization, i.e., second week after infarction (placebo, n = 122; verapamil, n = 128), after 1 month (placebo, n = 108; verapamil, n = 94) and after 16 months (placebo, n = 75; verapamil, n = 63) of treatment. The purpose was to evaluate the effect of verapamil on the prevalence and changes over time of arrhythmias and heart rate. In patients monitored twice, a significant increase of average ventricular premature complexes (VPC) per hour from before to 1 month (p = 0.0007) and 16 months (p = 0.02) after was demonstrated in the placebo group, and from before to 1 months (p = 0.01) after in the verapamil group. Average VPC/hr did not change from 1 to 16 months of treatment. A significant increment of > 10 VPC/hr was found after 1 (p = 0.03) and 16 months (p = 0.05) compared to prerandomization in the placebo, but not in the verapamil group. A significant increase of supraventricular arrhythmias after 1 month compared with prerandomization was found in the placebo group (p = 0.003) but not in the verapamil group. The prevalence of VPC and supraventricular tachycardia was significantly lower in the verapamil compared with the placebo group after 1 month of treatment. At 16 months no significant difference was found between the two groups. The 24 hour mean heart rate was significantly lower, 3 beats/min, in the verapamil compared with placebo after 1 and 16 months of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

[Differential diagnosis in acute chest pain and suspected myocardial infarction. A pilot study]

In half of the patients admitted with chest pain on suspicion of an acute myocardial infarction (AMI), this diagnosis is not confirmed (non-AMI). Both AMI and non-AMI patients have a mortality which exceeds the mortality of the background population in the years following discharge based on a high incidence of cardiac death. As a pilot investigation, a comprehensive investigation programme was tested in 32 consecutive non-AMI patients. The possible organic causes of acute chest pain were thus illustrated systematically in each individual patient. In ten of the patients, a definitive diagnosis was established within the first 24 hours of admission and no further investigation was thus performed. The remaining 22 patients participated in the planned investigation programme. In 30 of the patients (94%) a probable organic cause for the chest pain was found. This investigation demonstrates that the investigation programme is employable and it suggests that the cause of chest pain in non-AMI patients usually can be placed in one of the three main groups: 1) IHS, 2) oesophageal disease and 3) physiurgic conditions.

Independent prognostic risk factors for patients referred because of suspected acute myocardial infarction without confirmed diagnosis. Prognosis after discharge in relation to medical history and non-invasive investigations

Variables associated with risk of cardiac events, i.e. acute myocardial infarction (AMI) or cardiac death after discharge, were studied in patients who had been referred to coronary care units because of suspected AMI due to chest pain, but in whom this was not confirmed. The patients were all under 76 years of age, and were followed from 12 to 24 months, median 14 months. The estimated percentage without a cardiac event in 257 patients after one year was 91.3. On the basis of prognostic and clinical importance the analyzed variables included selected aspects of the medical history, electrocardiogram on admission in all 257 patients, subsequent electrocardiogram at rest, exercise test, thallium scintigraphy, chest X-ray, echocardiography, systolic time intervals and Holter monitoring when possible in 217 patients. Multivariate analysis identified combined electrocardiogram at rest and during exercise as the only variable with independent prognostic information. The presence of ST segment deviation, Q-wave, negative T-wave or intraventricular block in the electrocardiogram at rest or an abnormal ST segment response during exercise, increased the hazard of a cardiac event by a factor of 11.8. It is concluded that patients without confirmed AMI are at risk following discharge. These patients should undergo an exercise test and those with an abnormal electrocardiogram at rest and/or during exercise should be followed closely after discharge.

Antihypertensive effect of a non-selective (propranolol) and a cardioselective (metoprolol) beta-adrenoceptor blocking agent at rest and during exercise

1 The antihypertensive effects at rest and during physical exercise of the non-selective beta-adrenoceptor blocker propranolol and the cardioselective beta-adrenoceptor blocker metoprolol were compared in a double-blind cross-over study. 2 Eighteen patients with mild hypertension entered the trial. One patient was withdrawn from the study due to side effects on both drugs. 3 The two beta-adrenoceptor blockers were compared using doses earlier shown to have the same beta-adrenoceptor blocking potency, as measured by their effect on exercise tachycardia in healthy men. 4 Arterial blood pressure was reduced to the same extent by propranolol and metoprolol at rest as well as during submaximal work. 5 It is concluded that the antihypertensive effect of beta-adrenoceptor blockers is mainly mediated through blockade of the beta 1-adrenoceptors.

The mechanism of hypoxaemia after laparotomy

In 18 patients who were undergoing upper laparotomies the alveolo-arterial oxygen difference and right-to-left shunt were measured before the operation, on the first post-operative day, and in some cases also later in the post-operative period. The arterial oxygen tension was found to be considerably reduced post-operatively. The right-to-left shunt estimated by the hydrogen isotope technique was moderately increased in most instances, but the increase was far from large enough to account for the observed hypoxaemia. It is concluded that uneven distribution of ventilation relative to perfusion is the main cause of post-operative hypoxaemia, whereas veno-arterial shunt through atelectatic areas is of minor importance.

Right-to-left shunt in normal man determined by the use of tritium and krypton 85

An aqueous solution of tritium and krypton 85 together with Evans blue dye was injected intravenously in twelve normal subjects during quiet breathing, during apnea, and during voluntary hyperventilation. Arterial blood was sampled within the first 30 sec after the injection to measure the recovery of the two gases. Blood-gas partition coefficients of the two gases at 37 C were determined experimentally and the ratio between them was found to be 3.8 in normal blood. Knowing this ratio it is possible to calculate the fraction of the arterial recovery due to a right-to-left shunt, and that due to alveolar back pressure. The shunt calculated from findings during quiet breathing is 0.26% of the cardiac output. Recoveries during apnea lead to a calculated shunt of identical size, whereas the shunt calculated from the experiments during hyperventilation amounts to only 0.11% of the cardiac output.

Submitted on March 8, 1962