Non-invasive cardiovascular magnetic resonance pulmonary capillary wedge pressure predicts future atrial fibrillation: a LOOP substudy

INTRODUCTION: Elevated pulmonary capillary wedge pressure (PCWP) is known to drive atrial fibrillation (AF). However, it remains unknown if non-invasive cardiovascular magnetic resonance (CMR)-derived PCWP could predict the future risk of AF. This study investigated whether a CMR-derived measure of PCWP could predict future AF. METHODS: We enrolled 202 participants (mean age 76.2 ± 4.2 years) from the LOOP study, each receiving implantable loop recorder for continuous rhythm monitoring over 4 years. Cardiovascular magnetic resonance imaging quantified left atrial volume (LAV) and left ventricular mass, allowing calculation of a validated sex-specific equation derived PCWP. Cox proportional hazards analysis identified independent variables associated with incident AF. RESULTS: Eighty-six participants (42.6%) manifested AF during follow-up. Individuals with AF exhibited significantly higher CMR-PCWP (16.1 ± 2.8 vs 14.7 ± 2.3 mmHg, P < .01) and greater LAV. Univariate regression highlighted that PCWP ≥16 mmHg was significantly associated with incident AF [hazard ratio (HR): 2.73]. Stepwise Cox regression confirmed that PCWP ≥16 mmHg and the CHARGE-AF score remained independently associated with AF, with PCWP conveying higher HR (2.88, P < .001). Kaplan-Meier analysis reinforced the importance of this threshold for AF onset, demonstrating a significantly increased probability of arrhythmia over time and emphasizing its decisive clinical impact. CONCLUSION: Elevated CMR-PCWP is associated with AF in older, high-stroke-risk individuals, underscoring the role of subclinical diastolic dysfunction in promoting arrhythmogenesis. Incorporating non-invasive PCWP assessment into routine CMR evaluation may enhance risk stratification, allowing prompt identification of at-risk patients and enabling earlier, precise, targeted measures for AF prevention.