Impact of pulmonary hypertension on in-hospital outcomes among patients hospitalized with multiple myeloma: A 2015–2022 national inpatient sample analysis

Abstract

Abstract Background: Pulmonary hypertension (PH) is a serious disease that complicates a range of hematologic and cardiovascular disorders. However, its prevalence and prognostic impact in patients hospitalized with multiple myeloma (MM) remain not well understood. Given recent improvements in MM survival, comorbid conditions such as PH may increasingly influence in-hospital outcomes and resource utilization. Objectives: Using the National Inpatient Sample (NIS) database, we aimed to describe temporal trends in PH prevalence among MM hospitalizations from Q4 2015 to 2022, compare in-hospital mortality, length of stay (LOS), and total charges between MM patients with and without PH, and assess whether PH was independently associated with higher in-hospital mortality among patients hospitalized with MM. Methods: A retrospective study of the NIS database (Q4 2015–2022) was performed using ICD-10-CM codes to identify hospitalizations for MM and secondary diagnosis codes for PH. Hospitalizations were stratified by the presence or absence of PH. Annual PH prevalence per 1000 MM admissions was calculated using discharge weights and its temporal trend evaluated by survey-weighted linear regression. Weighted univariate chi-square tests and t-tests were used to compare in-hospital mortality, LOS and total charges between MM patients with and without PH. Multivariable survey-weighted logistic regression evaluated the independent association of PH with in-hospital mortality, adjusting for age, sex, race, ZIP-income quartile and hospital bed size. Survey-weighted linear regression assessed associations of PH with mean LOS and total hospital charges. Results: There were 143,605 MM hospitalizations during the study period, out of which 3000 (2.1%) had coexisting PH. Prevalence of PH rose from undetectable in 2015 to 29.3 per 1000 MM admissions in 2022, however, this upward trend did not reach statistical significance (p-trend = 0.125). MM patients with PH were older (mean age 70.9 years in the PH group vs. 65.4 years in the non-PH group; p < 0.001) and more often female (55% vs. 44%; p < 0.001). They also had a higher in-hospital complication burden, including acute heart failure (20% vs. 3%; p < 0.001), chronic heart failure (16% vs. 3%; p < 0.001), and atrial fibrillation (15% vs. 6%; p < 0.001). Crude in-hospital mortality was higher with PH than without (8.3% vs. 4.6%; p < 0.001), corresponding to an unadjusted odds ratio of 1.89 (95% CI 1.39–2.56; p < 0.001). After adjustment for age, sex, race, ZIP-income quartile, and hospital bed size, PH remained independently associated with higher mortality (adjusted OR 1.39; 95% CI 1.01–1.91; p = 0.044). Mean length of stay did not differ significantly between PH and non-PH groups (11.37 vs. 11.42 days; 95% CI -0.5667345 to 0.9622562; p=0.612), and mean total hospital charges likewise showed no significant difference ($154,763 vs. $147,231; 95% CI -23,161 to 47,100; p=0.504). Conclusion: Our NIS analysis shows that pulmonary hypertension in multiple myeloma hospitalizations is associated with higher in-hospital mortality and complications burden, despite similar lengths of stay and hospital charges. These findings support routine PH screening in MM patients and the early implementation of multidisciplinary care pathways. Further prospective studies are needed to determine whether such targeted interventions can improve in-hospital outcomes in this high-risk group.