Are changes in left ventricular volume as measured with the biplane Simpson's method predominantly related to changes in its area or long axis in the prognostic evaluation of remodelling following a myocardial infarction?

AIMS

Two-dimensional (2D) echocardiography has been widely applied to measure left ventricular volumes with the biplane Simpson's method in the assessment of left ventricular remodelling following an acute myocardial infarction. This volume formula is based upon tracings of endocardium and measurement of long axis on left ventricular images. In the present follow-up study of post-myocardial infarction patients we evaluated the prognostic impact of changes in left ventricular areas and geometry versus long axis to determine if only long-axis measurements may be used for prognostic purposes.

METHODS AND RESULTS

Two-dimensional echocardiographic video recordings of the apical four-chamber and long-axis views were obtained in 756 patients 2--7 days and 3 months following an acute myocardial infarction. All videotapes were sent to a core laboratory and left ventricular volumes were measured with the biplane Simpson's method in end-diastole and end-systole. During the first 3 months 44 patients had suffered one of the following end-points and were excluded: cardiac death, recurrent myocardial infarction, heart failure or chronic arrhythmia. Over a period of 3--24 months 58 such end-points occurred. With the Cox proportional hazards model the increase in left ventricular systolic volume was the strongest predictor for such events (Chi-square 18.5, P<0.0001), followed by an increase in end-systolic area (Chi-square 17.0, P<0.0001) and end-systolic spherity index (Chi-square 8.74,P =0.003). The increase in end-systolic long axis had only a borderline predictive value (Chi-square 4.3, P=0.04). The change in long-axis shortening from end-diastole to end-systole had no significant predictive value at all.

CONCLUSION

In the studied population changes in left ventricular area and geometry, but not in the long axis, were mainly related to cardiac morbidity. The proper assessment of changes in left ventricular dimensions should therefore be based upon tracings of the area and not on long axis measurements only.

[Echocardiographic findings, pro-ANP and treatment in acute myocardial infarction without overt heart failure]

This study was undertaken to characterise patients without overt heart failure and with a left ventricular ejection fraction > or = 40% 2-7 days following an acute myocardial infarction. Patients with an ejection fraction > or = 40% (n = 868) had a lower prevalence of anterior myocardial infarction (p < 0.001) and lower levels of N-terminal pro-ANP (atrial natriuretic peptide) (p < 0.001) than those with ejection fraction < 40% (n = 305). Patients with ejection fraction > or = 40% had smaller left ventricular volume and mass (p < 0.001). Pro-ANP levels did not correlate significantly with left ventricular volume or ejection fraction in this group. Among patients with ejection fraction < 40%; statistically significant correlations between pro-ANP levels and both ejection fraction and left ventricular endsystolic volume were found. 64% and 61% of patients in the two groups were given thrombolytic treatment. In this study, most patients with acute myocardial infarction had an ejection fraction > or = 40%. Pro-ANP levels were not correlated with the ejection fraction or left ventricular volume. Approximately two thirds of the patients received thrombolytic treatment.

Treatment of hypertensive and hypercholesterolaemic patients in general practice. The effect of captopril, atenolol and pravastatin combined with life style intervention

OBJECTIVE

To elucidate the effect on blood pressure and blood lipids of an angiotensin converting enzyme inhibitor (captopril), and a beta-receptor blocking agent (atenolol), given alone or in combination with a cholesterol reducing drug, the beta-hydroxy-methylglutaryl-coenzyme A reductase inhibitor pravastatin, in patients who were also encouraged to improve their lifestyle.

DESIGN

A longitudinal study consisting of three phases. I: Lifestyle intervention alone. II: Continued lifestyle intervention combined with captopril or atenolol. III: Continued lifestyle intervention combined with the same drugs as in phase II and in addition pravastatin or placebo.

SETTING

Fifty-four general practice surgeries in Norway.

PARTICIPANTS

Hypertensive patients, 210 females and 160 males, treated or untreated with antihypertensive drugs with a sitting diastolic blood pressure between 95 and 115 mmHg and a serum total cholesterol between 6.5 mmol/l (7.0 for those age 60-67 years) and 9.0 mmol/l.

RESULTS

The antihypertensive effect of captopril and atenolol was not influenced by concurrent administration of pravastatin. The effect of pravastatin was not limited by concurrent medication with captopril or atenolol. Improvement in lifestyle seemed to reduce the need for supplementary treatment with diuretics.

CONCLUSION

Pravastatin can be used in combination with captopril or atenolol in the treatment of hypertensive and hypercholesterolaemic patients.