Impact of Frailty on Inpatient Mortality and Resource Utilization for Primary Pulmonary Hypertension

Background  Frailty has been associated with inferior outcomes in patients with primary pulmonary hypertension (PPH). There is a lack of national data to assess if hospital frailty risk score (HFRS) is associated with worse inpatient outcomes in PPH. Methods  Our retrospective study used the Nationwide Readmission Database (NRD). First, we extracted all cases older than 18 years who were discharged with a principal diagnosis of PPH between January and November 2016 to 2019 to allow for a 30-day follow-up. Appropriate survey and domain analyses were applied to obtain national estimates using SAS 9.4. Results  We identified 4,555 cases. HFRS <5 was present in 56% ( n  = 2,555) of the cohort. Patients with an intermediate-to-high frailty risk score (HFRS ≥5) were older than those with a low frailty risk score (HFRS <5), with a mean age of 61 versus 54 years ( p  < 0.01), and had slightly fewer women (75 vs. 78%, p  = 0.09). Patients with HFRS >5 had a higher prevalence of dementia, depression, diabetes mellitus, malignancy, acute encephalopathy, coagulopathy, heart failure, and chronic (liver and renal) diseases ( p  < 0.01). Also, they had higher inpatient mortality during index admission (14 vs. 2%, p  < 0.001), and all-cause 30-day readmission rates (38 vs. 33%, p  = 0.01). Univariate analysis suggests a positive correlation between the degree of frailty and the odds of inpatient mortality (referenced to HFRS <5). The HFRS 5 to 10 group has an odds ratio (OR) of 5 (95% confidence interval [CI]: 3.3-8), the HFRS 10 to 15 group has an OR of 14 (95% CI: 8-23), and the HFRS >15 group has an OR of 20 (95% CI: 9-45). Even after adjusting for age, gender, and significant comorbidities, the single most important factor associated with higher odds of inpatient mortality was HFRS >5 (OR: 5.5 [95% CI: 3.7-8.3], p  < 0.001) followed by acute myocardial infarction, acute encephalopathy, heart failure, chronic liver disease, and malnutrition. Length of stay had linear trend with HFRS (mean of 6 days for HFRS <5 vs. 11 days for HFRS 5-10 vs. 19 days for HFRS >10, p  < 0.001). Conclusion  Adverse inpatient outcomes correlate with the severity of HFRS in PPH.