Abstract 579: Reduced Pressure-volume Response to Exercise May Reflect Subclinical Myocardial Disease in Type 2 Diabetes
Background: The predictive value of negative exercise stress echocardiography in subjects with type 2 diabetes (T2DM) is less than in those without T2DM. A reduced end-systolic pressure-volume (SP/ESV) response may identify at risk pts, but the pathophysiology of this finding has not been determined. We sought to identify if the abnormal SP/ESV response reflected subclinical diabetic heart disease.
Methods: Myocardial dysfunction was sought with resting and exercise echo in 168 apparently healthy T2DM (97 men, 55 ± 10 y). Ischemia was excluded by ExE. Conventional data, tissue velocity, strain and strain rate were acquired at baseline and peak stress from 6 basal segts in conventional apical views. ΔSP/ESV was calculated as [(peak stress systolic blood pressure/peak stress end systolic volume index) -(rest systolic blood pressure/rest end systolic volume index)].
Results: Post exercise, 83 subjects showed a ΔSP/ESV ≤12 mmHg/ml/m2. These patients were noted to have significantly lower resting diastolic tissue velocity, lower peak heart rates on exercise and poorer exercise capacity than those with ΔSP/ESV > 12 mmHg/ml/m2 [Table⇓]. There were no significant differences between the groups in terms of age, BMI, fasting glucose and systolic strain or strain rate. In a logistic regression model incorporating diastolic tissue velocity, peak heart rate and exercise capacity, all were significant univariate correlates of ΔSP/ESV, although exercise capacity was the strongest (OR= 0.88, p= 0.02).
Conclusions: ΔSP/ESV index correlates with resting diastolic tissue velocity, peak heart rate and exercise capacity, all of which have known prognostic implications in T2DM. The systolic response to stress may provide information analogous to that provided by diastolic dysfunction as a marker of subclinical disease.