Abstract
Background:
Diabetes is associated with accelerated vascular calcification and stiffening of the arteries. Reduced systemic arterial compliance (SAC) is regarded as a major factor in the development of hypertension, contributing to increased left ventricular afterload and myocardial oxygen demand and reduced coronary flow reserve. We thus hypothesized that reduced SAC is an independent predictor of mortality in patients with diabetes.
Methods:
We retrospectively analyzed data of 528 consecutive patients with type 2 diabetes who had a Doppler-echocardiographic exam in our institution. Blood pressure was measured in all patients at the time of echocardiography. SAC was calculated as the ratio of stroke volume index to arterial pulse pressure.
Results:
Follow up was completed in 97% of patients and mean follow-up time was 2.9±1.2 years. Mean age was 66±11 years with 68% males and 68% with coronary artery disease (CAD). Fifty percent of the patients had markedly reduced SAC on the basis of the cut-off value (SAC <0.6 ml/m
2
/mmHg) previously reported to be associated with adverse outcome in patients with hypertension. Patients with reduced SAC were significantly older (68±11 vs. 65±10, p=0.002) and had a higher prevalence of hypertension (78 vs. 22%, p<0.0001) and lower LV ejection fraction (51±15 vs. 57±13%, p=0.001). The prevalence of male gender, CAD, and obesity assessed with body mass index (BMI) was similar in patients with reduced SAC compared to those with higher SAC values. Five-year survival was significantly lower in patients with reduced SAC (68±5 vs. 87±4%, p<0.005). After adjusting for age, gender, LV ejection fraction, CAD, BMI, and blood pressure, reduced SAC remained a powerful and independent predictor of total mortality (Hazard ratio: 1.70 95% Confidence interval: 1.14 –2.58; p=0.008).
Conclusion
: Reduced SAC is encountered frequently in patients with type 2 diabetes and is a major risk factor for total mortality in this population. The SAC, which is easily measurable in the context of routine echocardiographic exam, should be taken into consideration when evaluating these patients with regards to prognosis and treatment.
Funded by:
Québec Heart Institute Foundation