Pre-clinical diabetic cardiomyopathy: prevalence, screening, and outcome

Diabetic cardiomyopathy, characterized by left ventricular (LV) dysfunction and LV hypertrophy independent of myocardial ischaemia and hypertension, could contribute to the increased life-time risk of congestive heart failure seen in patients with diabetes. We assessed prospectively the prevalence, effectiveness of screening methods [brain natriuretic peptide (BNP) and C-reactive protein in combination with clinical parameters], and outcome of pre-clinical diabetic cardiomyopathy.

We studied 100 adults (mean age 57.4 +/- 10.2 years, 44% females) with diabetes and no previous evidence of structural heart disease. By echocardiography, diabetic cardiomyopathy was present in 48% of patients. Screening with combinations of clinical parameters (gender, systolic blood pressure, and body mass index), but not BNP, resulted in high negative predictive values for diabetic cardiomyopathy. During a mean follow-up of 48.5 +/- 9.0 months, in the groups with and without diabetic cardiomyopathy, 12.5 vs. 3.9% (P < 0.2) patients died or experienced cardiovascular events and 37.5 vs. 9.6% (P < 0.002) had a deterioration in NYHA functional class. Overall event-free survival was 54 vs. 87% (P = 0.001) in the groups with and without diabetic cardiomyopathy, respectively. Brain natriuretic peptide was an independent predictor of events [odds ratio 3.5 (1.1-10.9), P = 0.02].

Pre-clinical diabetic cardiomyopathy is common. Screening with combinations of simple clinical parameters, but not BNP, can be useful to identify those patients needing further evaluation. Patients with pre-clinical diabetic cardiomyopathy are at increased risk for functional deterioration and possibly cardiovascular events during follow-up. Brain natriuretic peptide was shown to be an independent predictor of future events.