Heart failure and diabetes: left ventricular systolic function

Heart failure is the main cause of mortality and morbidity in general population, annual mortality rate is 20%, in spite of pharmacological treatments or other therapies. Cardio-vascular events and diabetes tight correlation is well known, while it is less evaluated diabetes and heart failure correlation is less studied, heart failure as left ventricular systolic function impairment. Cardiovascular disease rate is decreasing, systolic heart failure rate is raising. Our study goal is to evaluate which role diabetes plays in determining systolic heart failure, diagnosed by echocardiographical examination.

Four hundred and fifty consecutive patients, systolic heart failure prone, diagnosed by left ventricular ejection fraction less than 40%, were included. Exclusion criteria were rheumatic or congenital valve diseases. Mean age was 78.3 years (53-93 years), 286 were women and 164 men. Statistical analysis were performed by parametric t-Student test and not parametric chi2 test. High significant difference was assessed for P<0.05.

Seventy six (16.9%) patients were diabetes prone (D), 374 (83.1%) were diabetes free, so not diabetic (ND). Forty three men were D (56.5%), 131 ND (35%). Diabetic mean age was 74.7 years (52-88), not diabetic was 79.3 (53-93). Six D (7.8%) and 21 ND patients (5.6%) were hypercholesterolemia prone. Eight D (10.5%) and 18 ND (10.1%) patients were smokers. Twenty eight D (36.8%) and 107 ND patients (28.6%) were hypertensive. Thirty three D (43.4%) and 88 ND (26.4%) patients were coronary artery disease prone, 3 of 33 (3.9%) D and 28 of 88 (7.4%) ND ischemic patients were myocardial infarction prone. Twenty one D (27.6%) and 106 ND (28.3%) patients were atrial fibrillation prone. There were not statistical significant difference among D and ND patients for following variables: sex, smoke, total cholesterolemia, hypertension and atrial fibrillation. We found an high significant difference for mean age (P<0.005) and coronary artery disease prone patients (P<0.007), but not for myocardial infarction prone subjects (P<0.1).

Diabetes, not depending by other common cardiovascular risk factors, causes systolic heart failure, in prone patients, on an younger age, and in the same time an higher coronary artery disease rate, but not an higher myocardial infarction rate, because the coronary artery disease is often a microvascular one, and it leads to heart failure rather than myocardial necrosis.