Short-term Prognostic Value of Heart Rate Variability in Pulmonary Embolism Patients: 2-Center Cohort Study.

Purpose: Pulmonary thromboembolism (PTE) is the third most frequent acute cardiovascular syndrome, with serious sequelae in untreated patients. Heart rate variability (HRV) has emerged as a crucial and established prognostic indicator for adverse events. Nevertheless, its correlation with PTE and its prognostic significance in anticipating adverse outcomes warrant additional investigation. This study sought to examine the 30-day prognostic utility of HRV in predicting major adverse cardiovascular events (MACEs) in individuals with PTE.

Methods: This retrospective cohort study, conducted at 2 centers, enrolled 170 patients diagnosed with PTE and 174 control subjects who underwent 24-hour Holter recording, with an evaluation of time-domain HRV. PTE patients with simplified-Pulmonary-Embolism-Severity Index = 0 points are classified as a low-risk group, and ≥1 as an intermediate-risk group. The association between HRV and MACE was assessed using receiver operating characteristic curve analysis, Cox-regression, and Kaplan-Meier curve tests.

Findings: Time-domain HRV was reduced in all PTE patients compared with the control group and intermediate-risk PTE than in low-risk PTE groups (P < 0.05). A total of 22 PTE patients developed MACE during follow-up. PTE patients with reduced HRV have an increased risk of MACE (log-rank P < 0.05). HRV was an independent predictor of MACE, the standard deviation of all normal-to-normal RR intervals (hazard ratio [HR], 0.968; 95% CI, 0.950-0.986, P = 0.001), and the standard deviation of 5-minute mean N-N interval (HR, 0.974; 95% CI, 0.958-0.990, P = 0.002).

Implications: HRV is an independent risk factor and is associated with 30-day poor outcomes in PTE. Thus, HRV can be considered as a tool in the risk stratification of PTE patients.