Diagnostic accuracy of heart‐rate recovery after exercise in the assessment of diabetic cardiac autonomic neuropathy

• DOI: 10.1111/j.1464-5491.2012.03719.x
• Publication Date: 2012-06-04T18:45:31Z
• Authors: J. W. Sacre; C. L. Jellis; J. S. Coombes; T. H. Marwick
• Keywords: Male; Time Factors; Exercise test; Diabetic Cardiomyopathies; Diabetic autonomic neuropathy; 610; Sensitivity and Specificity; 796; Cohort Studies; Electrocardiography; 03 medical and health sciences; 0302 clinical medicine; Diabetic Neuropathies; Heart Rate; Risk Factors; Type 2 diabetes mellitus; Humans; Mass Screening; Prospective Studies; Exercise; Aged; Middle Aged; Heart-rate variability; 1310 Endocrinology; 3. Good health; Diabetes and Metabolism; 2712 Endocrinology; Sensitivity and specificity; Diabetes Mellitus, Type 2; ROC Curve; 2724 Internal Medicine; Exercise Test; Female

Diabet. Med. 29, e312–e320 (2012)AbstractAims Poor prognosis associated with blunted post‐exercise heart‐rate recovery may reflect autonomic dysfunction. This study sought the accuracy of post‐exercise heart‐rate recovery in the diagnosis of cardiac autonomic neuropathy, which represents a serious, but often unrecognized complication of Type 2 diabetes.Methods Clinical assessment of cardiac autonomic neuropathy and maximal treadmill exercise testing for heart‐rate recovery were performed in 135 patients with Type 2 diabetes and negative exercise echocardiograms. Cardiac autonomic neuropathy was defined by abnormalities in ≥ 2 of 7 autonomic function markers, including four cardiac reflex tests and three indices of short‐term (5‐min) heart‐rate variability. Heart‐rate recovery was defined at 1‐, 2‐ and 3‐min post‐exercise.Results Patients with cardiac autonomic neuropathy (n = 27; 20%) had lower heart‐rate recovery at 1‐, 2‐ and 3‐min post‐exercise (P < 0.01). Heart‐rate recovery demonstrated univariate associations with autonomic function markers (r‐values 0.20–0.46, P < 0.05). Area under the receiver‐operating characteristic curve revealed good diagnostic performance of all heart‐rate recovery parameters (range 0.80–0.83, P < 0.001). Optimal cut‐offs for heart‐rate recovery at 1‐, 2‐ and 3‐min post‐exercise were ≤ 28 beats/min (sensitivity 93%, specificity 69%), ≤ 50 beats/min (sensitivity 96%, specificity 63%) and ≤ 52 beats/min (sensitivity 70%, specificity 84%), respectively. These criteria predicted cardiac autonomic neuropathy independently of relevant clinical and exercise test information (adjusted odds ratios 7–28, P < 0.05).Conclusions Post‐exercise heart‐rate recovery provides an accurate diagnostic test for cardiac autonomic neuropathy in Type 2 diabetes. The high sensitivity and modest specificity suggests heart‐rate recovery may be useful to screen for patients requiring clinical autonomic evaluation.