Background: P-wave terminal force in lead V1 (PtfV1) irregularity has been associated with various cardiovascular conditions, including atrial fibrillation, left ventricular diastolic dysfunction, valvular heart disease, congestive heart failure, stroke, and mortality. However, its prognostic value for unstable angina (UA) has not been extensively studied. To address this knowledge gap, this study aimed to evaluate the long-term predictive significance of PtfV1 at discharge for UA patients.
Methods: A total of 707 patients with newly diagnosed UA were included in this study. PtfV1 measurements were recorded at admission and discharge. PtfV1(+) was defined as an absolute value above 0.04mm·s, while PtfV1(-) was defined as an absolute value below 0.04mm·s. Based on their PtfV1 values at discharge, patients were categorized into two groups: PtfV1(-) and PtfV1(+). Univariate and multivariate regression analyses were conducted to identify variables that could potentially contribute to the risk of UA.
Results: Univariate analysis revealed a higher incidence of total adverse outcomes and major adverse cardiovascular events (MACE) in the PtfV1(+) group compared to the PtfV1(-) group, with a risk ratio (RR) of 2.006 [95% confidence interval (95% CI): 1.389– 2.896] for total outcomes and an RR of 2.759 (95% CI: 1.870– 4.070) for MACE. After adjusting for confounding factors through multivariate analysis, participants with PtfV1(+) had a 46% increased risk [adjusted hazard ratio (HR): 1.458; 95% CI: 1.010– 2.104]for total adverse outcomes and an 86% increased risk (adjusted HR: 1.863; 95% CI: 1.246– 2.786) for MACE compared to those with PtfV1(-).
Conclusion: The presence of PtfV1(+) at discharge is an independent predictor of poor outcomes and provides extended prognostic information for UA patients.

Keywords: P wave terminal force in lead V1, PtfV1, unstable angina, UA, prognosis, electrocardiography, major adverse cardiovascular events, MACE