Outcomes of heart failure with preserved ejection fraction (HFpEF) in patients with and without cardiac amyloidosis: analysis from 2016–2019 national inpatient sample

Abstract

Abstract Background Cardiac amyloidosis (CA), a restrictive cardiomyopathy that leads to heart failure, is often under-diagnosed in its early-stages, leading to patients being diagnosed with it in advanced stages. Most patients presenting with heart failure are presumed as non-amyloid heart failure due to a lack of awareness. A high degree of clinical suspicion is of paramount importance for early diagnosis and management of CA because the extent of cardiac involvement determines overall prognosis. Purpose Our study highlights the outcomes of HFpEF in patients with and without CA. Methods This is a retrospective cohort study involving principal hospitalizations for HFpEF between January 1, 2016 and December 31, 2019 from the National Inpatient Sample (NIS), the largest all-payer public database of hospital care data in the United States. Our study sample included discharged adult patients (≥18 years) hospitalised for HFpEF using ICD-10 codes validated in previous studies. Confounders were adjusted using multivariable regression analysis. Results During the study period, there were 87,219 index hospitalizations for HFpEF. Among them, 38.3% (n=33405) were males, 61.7% (n=53814) were females, and 0.24% (n=209) had CA. Racial distribution is as follows: 76% Whites, 13.4% Blacks, 6.4% Hispanics, and 4.2% other races. Mean patient age was 74.6±13.2 years, and 68.1% were on Medicare. A total of 59,135 (67.8%) hospitalizations had a Charlson Comorbidity Index (CCI) of >3, with an in-hospital mortality of 2.5%. Compared to the non-CA cohort, the CA cohort had lower prevalence of diabetes mellitus (8.5% vs 27%, p<0.0001) and COPD (23.5% vs 46.8%, p<0.001) but a higher prevalence of renal disease (51.6% vs 41.9%, p=0.004), cancer (25.4% vs 4.2%, p<0.001) and greater incidence of cardiogenic shock (5.2% vs 0.5%, p<0.001). Compared to the non-CA cohort, patients with CA were less likely to be female (38% vs 61.7%, p<0.001), were of similar age (mean age 74.7 vs 74.6 yrs, p=0.907), had longer length of hospital stay (LOS, 6.7 vs 5.1 days, p<0.001), higher in-hospital mortality (5.2% vs 2.5%, p=0.023), and a higher likelihood of having a CCI >3 (74.2% vs 67.8%, p=0.017). Multivariate regression analysis showed that subjects in the CA cohort had significantly increased adjusted odds of in-hospital mortality (aOR=2.2; 95% CI: 1.2–4.4; p=0.017) and cardiogenic shock (aOR=9.5; 95% CI: 5–17.9; p<0.001) than those in the non-CA cohort after adjusting for age, sex, race, and CCI. Conclusions Our study illustrates that patients with a history of CA admitted for HFpEF had greater incidence of cardiogenic shock, higher prevalence of renal diseases and cancer with a longer LOS, and higher in-hospital mortality. Funding Acknowledgement Type of funding sources: None.