Smartwatch-detected pulse irregularities were associated with a higher frequency of subsequent cardiovascular diagnoses. An analysis presented at the American Heart Association (AHA) 2025 Scientific Sessions evaluated the association between irregular pulse notifications and cardiovascular outcomes among participants enrolled in the Apple Heart Study.

The analysis included 288,533 adults who completed the end-of-study (EOS) survey from a total enrolled population of more than 400,000 participants. Participants were categorized based on receipt of IPNs from a smartwatch. Self-reported cardiovascular diagnoses included HF, MI, stroke, TIA, and PE. Associations were evaluated using adjusted logistic regression models accounting for age, sex, and CHA₂DS₂-VASc risk score components.

The EOS survey was completed by 908 participants who received IPNs, representing 42% of the IPN cohort, and by 287,625 participants who did not receive IPNs, representing 69% of the non-IPN cohort. Participants who received IPNs were older, more frequently male, and had a higher burden of comorbid conditions and CVD risk factors than the overall study population. Higher rates of HF, MI, stroke, TIA, and PE were reported in the IPN cohort compared with participants who did not receive IPNs. Fully adjusted logistic regression analyses demonstrated increased odds of each cardiovascular diagnosis among participants who received IPNs.

These findings indicate that smartwatch-detected IPNs identify individuals with elevated underlying cardiovascular risk. Such alerts may represent a clinically relevant signal for cardiovascular evaluation beyond atrial fibrillation detection.