Rising Cardiovascular Mortality Despite Increased Resource Utilization: Insights From the Nationwide Inpatient Sample Database

Introduction The global burden of cardiovascular disease (CVD) has risen over the past decade, potentially escalating resource utilization, morbidity, and mortality. We analyzed trends in hospitalization for CVDs, outcomes of hospitalizations, and the impact of the COVID-19 pandemic on CVD hospitalizations between 2016 and 2020. Methods Adult CVD hospitalizations recorded in the 2016-2020 nationwide inpatient sample (NIS) were identified using major diagnostic categories (MDC- class 5). The NIS is the largest all-payer repository of all hospitalizations in the USA within a calendar year. We compared sociodemographic factors and outcomes (mortality, length of stay, and hospital charges) of CVD hospitalization before and during the pandemic using Pearson's χ2 tests. We used Stata ranking commands and ICD-10 (10th revision of the International Statistical Classification of Diseases and Related Health Problems) codes to identify the most recurring diagnoses associated with CVD mortality during the study period. Trends in mortality and resource use were assessed using the Jonckheere-Terpstra trend test. Hospital charges were adjusted for inflation using the Medical Expenditure Panel Survey index. We used stepwise multivariate logistic regression analyses (P ≤ 0.05 for entry; P > 0.10 for removal) to identify covariates associated with cardiovascular mortality during the study period. Results Hospitalizations for CVDs rose from 4,283,502 in 2016 to 4,635,246 in 2019 (P_trend < 0.001) and declined to 3,865,399 in 2020. 452,930 mortalities were recorded during the study period. In-hospital mortality rose from 111,090 (2.6%) in 2016 to 118,825 (2.8%) in 2020 (P_trend < 0.001). Compared with the prepandemic years, mortality rates were higher during the pandemic (108,231 [2.8%] vs. 445,373 [2.5%]; P<0.001), and increased in hospitalizations for hypertensive heart disease with chronic kidney disease (CKD) (15,585 [14.4%] vs. 45,873 [10.3%]; P<0.001), hypertensive heart disease with heart failure (7,468 [6.9%] vs. 21,378 [4.8%]), ventricular tachycardia (2,056 [1.9%] vs. 7,571 [1.7%]; P=0.022), and peripheral angiopathy with gangrene (1,191 [1.1%] vs. 3,118 [0.7%]; P<0.001). CVD hospitalizations totaled 80.3 million hospital days and 39.7 million hospital procedures during the period. The mean number of procedures (3 vs. 2) and mean length of hospital stay (5.6 vs. 4.5 days) increased during the pandemic (P<0.001). The mean hospital cost for CVD increased from US$ 69,394 in 2016 to US$ 89,728 in 2020 (P_trend < 0.001). Conclusion CVD mortality increased despite increased resource use over the study period. Hospitalizations during the pandemic had poorer mortality and resource use outcomes than those in the preceding years.