Evaluation of restenosis and extent of coronary artery disease in patients with previous percutaneous coronary interventions by dobutamine stress real-time myocardial contrast perfusion imaging

Objectives: To assess the accuracy of real-time myocardial contrast perfusion imaging (MCPI) for the diagnosis of restenosis and extent of coronary artery disease (CAD) in patients with previous percutaneous coronary intervention (PCI). Methods: 56 patients were studied 1.9 (SD 1.4) years after PCI. They underwent MCPI with commercially available ultrasound contrast agents (Optison or Definity) at rest and at peak dobutamine-atropine stress. Coronary angiography was performed within one month. Significant CAD was defined as ≥ 50% stenosis in ≥ 1 major epicardial coronary artery. Significant restenosis was defined as ≥ 50% stenosis in a coronary segment with previous intervention. Results: Reversible perfusion abnormalities were detected in 40 of 43 patients with significant CAD and in 4 of 13 patients without (overall sensitivity 93%, 95% CI 85% to 99%; specificity 69%, 95% CI 44% to 94%; and accuracy 88%, 95% CI 79% to 96%). Significant restenosis in ≥ 1 coronary artery with previous PCI was detected in 38 (68%) patients. Reversible perfusion abnormalities were present in 35 of them (sensitivity 92%, 95% CI 84% to 99%). Reversible perfusion abnormalities were detected in ≥ 2 vascular distributions in 20 of 28 patients with multivessel CAD and in 3 of 28 patients without (sensitivity 71%, 95% CI 55% to 88%; specificity 89%, 95% CI 78% to 99%; and accuracy 80%, 95% CI 70% to 91%). Restenosis was detected in 41 coronary arteries. Sensitivity of MCPI for regional diagnosis of restenosis was 73% (95% CI 60% to 87%), specificity was 75% (95% CI 60% to 90%), and accuracy was 74% (95% CI 64% to 84%). Conclusion: Dobutamine stress MCPI is a useful technique for the evaluation of restenosis and extent of CAD after PCI.