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

<b>Background</b> 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. <b>Methods</b> 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. <b>Results</b> We identified 4,555 cases. HFRS <5 was present in 56% ( <i>n</i> = 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 ( <i>p</i> < 0.01), and had slightly fewer women (75 vs. 78%, <i>p</i> = 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 ( <i>p</i> < 0.01). Also, they had higher inpatient mortality during index admission (14 vs. 2%, <i>p</i> < 0.001), and all-cause 30-day readmission rates (38 vs. 33%, <i>p</i> = 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], <i>p</i> < 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, <i>p</i> < 0.001). <b>Conclusion</b> Adverse inpatient outcomes correlate with the severity of HFRS in PPH.