Prevalence and prognostic value of subclinical coronary artery disease detected with CT for left atrium and pulmonary veins in patients undergoing atrial fibrillation ablation (PROCADAF Study)

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Clinical predictors such as persistent AF, increased left atrial volume and metabolic syndrome have been demonstrated to be associated with AF recurrence after ablation procedure (ATC). However, the impact of coronary heart disease (especially subclinical) and revascularization procedures on the outcome of rhythm control after ATC has not been extensively investigated.

Aim of the study is to retrospectively evaluate the incidence of subclinical CAD in a population of patients with Atrial Fibrillation (AF) that underwent CT examination for left atrium and pulmonary veins assessment for ablation procedure planning and its correlation with post procedural AF recurrency.

327 patients that underwent CT for left atrium and pulmonary veins for ablation procedure planning with post procedural clinical follow up were enrolled. Patients were divided into 2 groups (Group 1: known CAD / previous revascularization procedure, and Group 2: no history of CAD). CT exams of Group 2 patients were retrospectively evaluated to assess the presence of subclinical CAD. No quantification of coronary stenosis was performed. The correlation between clinical / procedural outcome and AF recurrence in the two groups during a mean follow up time of about 3 years, 2 years, 1 year and 6 months was compared by Kaplan-Meier curves.

51 patients had known history of CAD (Group 1). 269 patients had no history of CAD (Group 2). In group 2 CT revision showed the presence of subclinical CAD in 121 pts (45%). Overall AF recurrency after ATC was recorded in 17 out of 51 patients of group 1 (33%) and in 74 out of 269 patients (28%) of group 2. In group 2 CT showed coronary atheromatosis in 121 pts. Kaplan-Meier curves showed no significant differences in AF recurrency between Group 1 and Group 2 during all followup ranges. In Group 2 a higher AF recurrency rate in patients with CT positive for subclinical CAD during a mean follow up period of 2 years (p 0.015) was showed by Kaplan-meier analysis while slighty significant recurrency was observed during a 1 year followup (p 0.043). Not significant recurrency rate was observed during the 6 months follow up nor in longer follow up. Moreover in group 2 patients recurrency rate was significantly correlated to use of β-blockers during a 2 yy follow-up.

In patients without known history of CAD, the presence of subclinical CAD was associated with higher rate of AF recurrency during a mean follow up of both 1 and 2 years after ablation procedure. Detection of subclinical CAD in patients undergoing ATC has potential clinical indications for cardiac arrhythmia management and support the potential role of cardiac CT before procedural planning in the downstrem management of patients without history of CAD.