Cardiac allograft vasculopathy: coronary computed tomography and virtual histology assessment.

INTRODUCTION: Cardiac allograft vasculopathy remains the leading cause of late morbidity and mortality in heart transplantation. The main diagnostic methods, coronary angiography or intracoronary ultrasound (when angiography is normal), are invasive. Other study methods, such as coronary computed tomography (CT) and virtual histological analysis, have not been widely assessed in this condition. OBJECTIVE: The objective of this study was to assess the correlation between data obtained from analysis of virtual histology compared with those obtained from the performance of coronary CT in cardiac transplant recipients. MATERIALS AND METHODS: During the same admission we performed coronary angiography and intravascular ultrasound with virtual histological analysis (automatic pull-back in anterior descending artery and one additional vessel if the former was normal) as well as coronary CT. RESULTS: The study included 10 patients. Virtual histology was done in segments with intimal thickening>0.5 mm, defining 2 groups of plaque, those with an inflammatory component (necrotic core>30% and calcium) versus those without it defined as the combination of both being <30%. A calcium component of the inflammatory plaque allowed coronary CT detection. CONCLUSIONS: The detection of inflammatory plaque in graft vessel disease can be based on an initial noninvasive method, such as coronary CT, although confirmation requires further study.

Safety and effectiveness of ivabradine after cardiac transplantation.

BACKGROUND: Heart denervation is the primary cause of sinus tachycardia in transplant recipients. Drugs are usually needed to treat associated symptoms. OBJECTIVE: To evaluate the safety and effectiveness of the novel I(f) channel antagonist ivabradine to control heart rate after transplantation. METHODS: Of 316 heart transplant recipients at a single center since 1991, ivabradine was administered in 15 patients, in addition to ß-blockers in 4 patients and contraindication to use of ß-blocker therapy in the others. A prospective follow-up study was conducted to identify possible adverse effects, tolerance, and drug effects on heart rate and control of symptoms. RESULTS: Of the 15 patients, 13 were men; overall mean (SD) patient age was 46 (4.6) years. In all patients, treatment was begun after verification of basal heart rate greater than 100 bpm and after other causes of sinus tachycardia had been ruled out. During follow-up of 1.13 (0.3) years, no substantial adverse effects were observed. It was possible to reach the maximum drug dosage in all patients, achieving a reduction in basal heart rate of 33 (6.2) bpm. All patients reported substantial clinical improvement, and demonstrated an increase in functional class. CONCLUSION: Ivabradine is safe, well tolerated, and effective in heart transplant recipients.