Sex Differences in the Prognosis of Non-Sustained Ventricular Tachycardia Detected on Holter Recording

Background Non-sustained ventricular tachycardia (NSVT) is a common finding during cardiac evaluation and has been linked to increased mortality. While some studies report a sex difference, most data stem from research cohorts. Objective This study aimed to assess the prognostic significance of NSVT in a real-life outpatient clinic, focusing on sex differences in mortality. Methods Analysis was performed on a cohort of consecutive patients referred to 48-hour Holter monitoring between 2009 and 2011 at Copenhagen University Hospital - Bispebjerg. Indications for Holter monitoring included palpitations, dizziness, syncope, or arrhythmia testing. Baseline characteristics, blood tests, echocardiography results, and mortality data were obtained from electronic patient records. Results 762 females (mean age 59±18 years) and 693 males (mean age 59±17 years) were enrolled. At least one episode of NSVT was detected in 9.7% of females and 20.6% of males. The median follow-up was 8.3 years. 20% of females and 24% of males died during follow-up.In multivariable models, NSVT was linked to mortality in males (HR: 1.6, 95% CI: 1.1-2.3) but not in females (HR: 1.2, 95% CI: 0.7-2.1).In case-control pairs matched on the propensity of being male conditional on relevant risk factors, NSVT was again linked to mortality in males (HR: 3.1 (2.0-4.8) but not in females (HR: 1.4 CI: 0.8-2.4). Conclusion In consecutive patients referred to symptom driven Holter monitoring, NSVT was associated with elevated all-cause mortality in males but not in females. These results can contribute to the risk assessment of patients presenting with NSVT.