Knud Skagen

Influence of gender on short- and long-term mortality after acute myocardial infarction

The aim of this study was to assess differences in short- and long-term mortality between male and female patients with acute myocardial infarction (AMI). The study population consisted of 6,676 consecutive patients admitted alive with an enzyme-confirmed AMI to 27 Danish hospitals from 1990 to 1992. Five patients were excluded because of missing information. Female patients (n = 2,170) were on average 5 years older than male patients (n = 4,501, p <0.001), had lower body mass index, and more often had diabetes, hypertension, and congestive heart failure. Left ventricular systolic function was the same for men and women. Women received thrombolytic therapy less often. The 1-year mortality for female patients was 28 +/- 1% and for men 21 +/- 1% (p <0.001). The unadjusted risk ratio associated with male gender in a proportional-hazards model was 0.76 (95% confidence intervals [CI] 0.70 to 0.83). Adjustment for age removed the importance of gender, and the risk ratio associated with male gender was 1.06 (95% CI 0.97 to 1.2, p = 0.2). An introduction of further variables in the model did not change this. Subdividing mortality into 6-day, 30-day, and late mortality demonstrated a significantly increased mortality in women in the short-term (6 and 30 days), with a risk ratio in men of 0.58 (95% CI 0.42 to 0.81) and 0.80 (95% CI 0.65 to 0.99), respectively. From day 30 onward there was an increased mortality in men with a risk ratio of 1.16 (95% CI 1.03 to 1.31, p = 0.01). Thus, women admitted alive to the hospital with an AMI have an increased long-term mortality that is explained by their older age. However, short-term mortality in women seems to increase independently of other risk factors, but is later followed by an increase in mortality in men.

Prognosis of late versus early ventricular fibrillation in acute myocardial infarction

To determine the prognosis of late ventricular fibrillation (VF) after acute myocardial infarction (AMI), the length of the monitoring period after AMI was extended. All patients in this series were continuously monitored in a coronary care unit to ensure observation of all VF within 18 days of AMI. From 1977 to 1985, 4,269 patients were admitted with AMI and 413 (9.6%) had in-hospital VF. Of these 281 (6.8%) had early VF (less than 48 hours after AMI) and 132 (3.2%) had late VF (greater than or equal to 48 hours after AMI). In-hospital mortality was 50 and 54% for early and late VF, respectively (p = 0.31). Kaplan-Meier survival analysis showed better survival after discharge for patients with early versus late VF (p = 0.009) but this difference was fully explained by the presence of heart failure. Survival analysis showed the same prognosis after 1, 3 and 5 years for early and late VF, when VF was not associated with heart failure. When VF was associated with heart failure (secondary VF) early VF had a greater mortality than late VF after 2 and 5 years. Logistic regression analysis showed that heart failure (relative risk 1.9 [1.1 to 3.1]) and cardiogenic shock (relative risk 3.9 [1.8 to 8.5]) were significant risk factors for in-hospital death. Late VF compared to early VF had no prognostic implication (relative risk 1.0 [0.6 to 1.6]). For patients discharged from the hospital, risk factors were heart failure (1.8 [1.1 to 2.8]) and previous AMI (1.6 [1.3 to 2.1]).(ABSTRACT TRUNCATED AT 250 WORDS)

First passage radionuclide cardiography for determination of cardiac output: evaluation of an improved method

A noninvasive method for determination of cardiac output by aid of first passage radionuclide cardiography is presented. As opposed to most other scintigraphic methods, a forward blood flow is measured, even in patients with valvar incompetence. In addition, the technique allows measurement of cardiac output in the presence of cardiac arrhythmias. No geometrical assumptions, corrections for radiation attenuation, loss of tracer, or empirical correction factors due to extracardiac radioactivity are required. We have evaluated the method in 19 patients with various heart diseases by comparison of the radionuclide cardiac outputs with those derived from the thermodilution technique performed simultaneously. Eight patients had valvar incompetence and 2 had cardiac arrhythmias. The mean radionuclide and thermodilution cardiac output values were 5.03 l/min (SD 1.21) and 5.18 l/min (SD 1.09), respectively. The 95% confidence interval for the bias was -0.40 to 0.10 l/min, and correlation analysis demonstrated an excellent correlation between results obtained with the two methods, r = 0.91 (P less than 0.001). This study shows that the improved gamma camera method represents a valid noninvasive technique for determination of cardiac output.

Different Effects of Calcium Antagonist and Beta-Blocker Therapy on Left-Ventricular Diastolic Function in Ischemic Heart Disease

Objective: To compare the effect of a calcium antagonist and a beta-blocker on left-ventricular diastolic function in patients with ischemic heart disease. Methods: 138 patients with chronic stable angina pectoris were randomized in a multicenter, double-blind trial to treatment with either mibefradil or atenolol for 6 weeks (50 mg once daily for 2 weeks followed by 100 mg once daily for 4 weeks). The ratio between early (E) and late (A) diastolic mitral flow velocities (E/A), the E wave deceleration time (DT) and the left ventricular isovolumetric relaxation time (IRT) were measured by Doppler echocardiography as parameters of left-ventricular diastolic function initially, after 4 and after 6 weeks of treatment. Results: Mibefradil did not change the E/A ratio significantly (+4%, NS), while atenolol treatment resulted in a significant increase in the E/A ratio (+20%, p < 0.001). Mibefradil treatment, on the other hand, resulted in a significant decrease (–8%, p < 0.001) in IRT, while atenolol treatment did not change IRT. Neither mibefradil nor atenolol treatment changed DT significantly. Conclusions: Both mibefradil and atenolol treatment significantly improves echocardiographic indices of left-ventricular diastolic function in patients with chronic stable angina. However, they affect different parameters and thus apparently act through different mechanisms.

Effects of amlodipine and isosorbide dinitrate on exercise-induced and ambulatory ischemia in patients with chronic stable angina pectoris

This study was designed to compare once-daily administration of 5–10 mg amlodipine with two daily doses of 40 mg sustained-release isosorbide dinitrate in 59 patients with stable angina using a randomized, double-blind, crossover study design. Anginal episodes, nitroglycerin consumption, and possible adverse events were recorded in a diary. A maximal symptom-limited bicycle exercise test and 48-hour ambulatory ECG monitoring were performed at baseline and at the end of each 5-week period of therapy. Exercise time, time to angina, time to ST depression, and maximal ST depression were measured during exercise. During ambulatory monitoring, the number of ischemic episodes and the duration per hour of ST depression were assessed. Amlodipine significantly reduced anginal episodes (P < 0.001) when compared with isosorbide dinitrate. Furthermore, amlodipine prolonged time to ST depression (P < 0.001) and time to angina (P < 0.05) when compared with isosorbide dinitrate. The number and duration of ischemic episodes during ambulatory monitoring were significantly reduced with amlodipine when compared with baseline values (P < 0.05), whereas no differences were found between isosorbide dinitrate and baseline. Adverse events were reported more frequently with isosorbide dinitrate than with amlodipine (P < 0.02). Amlodipine appears to be more effective and tolerable than sustained-release isosorbide dinitrate as monotherapy for chronic stable angina.

Closed mitral valvulotomy after the age of fifty.

This retrospective study is based upon a consecutive series of 90 patients with mitral stenosis who had their first closed mitral valvulotomy after the age of fifty. All patients were operated on during the period 1959--70 and were followed-up for at least 5 years until July 1, 1976. Calculated survival curves were compared with those of a group of 68 patients over fifty whose mitral stenosis was medically treated. The surgical mortality was 7.8%, largely due to the high mortality among patients in functional class IV. The late mortality rate after valvulotomy was significantly higher than in a matched population of the same age and sex, but significantly lower than in the medically treated patients. According to functional classification, the patients had improved markedly at the time of follow-up. High incidences of atrial fibrillation and late thromboembolic complications were noted. This study supports the view that closed mitral valvulotomy can be performed safely in patients over fifty with mitral stenosis without significant mitral regurgitation and heavy clacifications in functional classes II and III.

Reliability of first-pass radionuclide determination of cardiac output in the upright position at rest and during exercise

The reliability of non-invasive determination of cardiac output using first-pass radionuclide cardiography at rest and during exercise in the upright position was evaluated in 20 patients with coronary artery disease. Cardiac output values ranged from 2.97 to 5.99 1/min at rest and from 5.08 to 10.821/min during exercise. Cardiac output results obtained by the radionuclide method were compared with those derived from the thermodilution technique performed simultaneously. The mean difference between the two techniques was 0.02 1/min at rest and −0.341/min during exercise; the limits of agreement (mean±1.96 SD) were −1.29 to 1.33 1/min and −1.97 to 1.29 1/min, respectively, indicating an acceptable level of agreement. A high reproducibility of the radionuclide technique was found, with a mean difference between determinations by two observers of 0.03 1/min at rest and 0.21 1/min during exercise, the corresponding limits of agreement being −0.75 to 0.811/min and −0.79 to 1.21 1/min, respectively. With the aid of a variance component analysis of two determinations by each of four observers, 95% confidence intervals of ±10% at rest and ±12% during exercise were computed for the radionuclide cardiac output measurements. The observer variation was most pronounced for the part of the cardiac output determination related to measurement of left ventricular equilibrium activity during exercise. First-pass radionuclide cardiography is a reliable method for determination of cardiac output in cardiac patients at rest and during exercise in the upright position.