Efficacy of coronary angioplasty for the treatment of hibernating myocardium

Abstract

OBJECTIVES To determine the efficacy of coronary angioplasty as the sole method of revascularisation in patients with coronary artery disease and chronically dysfunctional but viable myocardium (hibernating myocardium), and to assess the effect of restenosis on functional outcome.

DESIGN AND PATIENTS 24 consecutive patients with hibernating myocardium were studied. Positron emission tomography was used to assess myocardial viability, blood flow, and flow reserve. One patient refused angioplasty, one had bypass surgery, and one died while waiting for an elective procedure. The procedure failed in three patients. The remaining 18 patients had repeat echocardiography, 15 had repeat coronary angiography, and nine had repeat assessments of blood flow and flow reserve at mean (SD) 17 (2) weeks after angioplasty. In three patients restenosis was documented.

RESULTS The wall motion score index in the revascularised territories improved from 1.71 (0.37) to 1.34 (0.47) (p = 0.008). Thirty of 51 dysfunctional segments improved in territories without restenosis compared with three of 14 in restenosed territories (p = 0.001). Hibernating and normal segments had comparable flows (0.82 (0.26) v0.89 (0.24) ml/min/g; NS) while flow reserve was lower in hibernating segments (1.55 (0.68) v 2.07 (1.08); p = 0.03). In segments without restenosis flow reserve improved from 2.03 (1.25) to 2.33 (1.4) (p = 0.03). Sensitivity, specificity, and positive and negative predictive accuracy of the viability study were 97%, 77%, 82%, and 96%, respectively. After excluding patients with restenosis, specificity and positive predictive accuracy improved to 90% and 93%.

CONCLUSIONS Angioplasty improves function in hibernating myocardium, and restenosis prevents recovery; hibernating myocardium is characterised by an impairment of flow reserve; restenosis affects the diagnostic accuracy of viability studies.