Outcome from balloon induced coronary artery dissection after intracoronary [beta] radiation

OBJECTIVE To evaluate the healing of balloon induced coronary artery dissection in individuals who have received β radiation treatment and to propose a new intravascular ultrasound (IVUS) dissection score to facilitate the comparison of dissection through time. DESIGN Retrospective study. SETTING Tertiary referral centre. PATIENTS 31 patients with stable angina pectoris, enrolled in the beta energy restenosis trial (BERT-1.5), were included. After excluding those who underwent stent implantation, the evaluable population was 22 patients. INTERVENTIONS Balloon angioplasty and intracoronary radiation followed by quantitative coronary angiography (QCA) and IVUS. Repeat QCA and IVUS were performed at six month follow up. MAIN OUTCOME MEASURES QCA and IVUS evidence of healing of dissection. Dissection classification for angiography was by the National Heart Lung Blood Institute scale. IVUS proven dissection was defined as partial or complete. The following IVUS defined characteristics of dissection were described in the affected coronary segments: length, depth, arc circumference, presence of flap, and dissection score. Dissection was defined as healed when all features of dissection had resolved. The calculated dose of radiation received by the dissected area in those with healed versus non-healed dissection was also compared. RESULTS Angiography (type Aâ[euro][per thousand]=â[euro][per thousand]5, Bâ[euro][per thousand]=â[euro][per thousand]7, Câ[euro][per thousand]=â[euro][per thousand]4) and IVUS proven (partialâ[euro][per thousand]=â[euro][per thousand]12, completeâ[euro][per thousand]=â[euro][per thousand]4) dissections were seen in 16 patients following intervention. At six month follow up, six and eight unhealed dissections were seen by angiography (Aâ[euro][per thousand]=â[euro][per thousand]2, Bâ[euro][per thousand]=â[euro][per thousand]4) and IVUS (partialâ[euro][per thousand]=â[euro][per thousand]7, completeâ[euro][per thousand]=â[euro][per thousand]1), respectively. The mean IVUS dissection score was 5.2 (range 3-8) following the procedure, and 4.6 (range 3-7) at follow up. No correlation was found between the dose prescribed in the treated area and the presence of unhealed dissection. No change in anginal status was seen despite the presence of unhealed dissection. CONCLUSION β radiation appears to alter the normal healing process, resulting in unhealed dissection in certain individuals. In view of the delayed and abnormal healing observed, long t