Readmission and Cardiorenal Syndrome in Heart Failure With Reduced Ejection Fraction

High 30-day readmission is associated with cardiorenal syndrome (CRS) in patients with heart failure with reduced ejection fraction (HFrEF). Worse renal disease is associated with higher 30-day readmission and higher all-cause mortality. These are among study findings published in the International Journal of Cardiology.

Investigators sought to assess 30-day readmission rates and clinical outcomes in CRS patients with HFrEF. The primary outcomes were 30-day readmission and all-cause mortality. Secondary outcomes were complication prevalence associated with CRS-related readmission.

They conducted a retrospective, observational cohort study using data from the Nationwide Readmissions Database to identify CRS-related hospitalizations (38.6% women) for HFrEF with different stages of chronic kidney disease (CKD) from 2018 through 2019. CRS was defined by ICD-10 codes. The investigators identified morbidities and patient characteristics. Only patients with chronic HFrEF were included. Patients less than 18 years of age and those discharged in December were excluded.

The investigators observed the comorbidities of obesity, chronic obstructive pulmonary disease, tobacco usage, and hyperlipidemia to be more common in patients with CKD stage I to II and CKD stage III to IV. Patients with stage V or higher had a higher rate of diabetes. Alcohol use was more common in patients with CKD stage I to II.

The investigators identified more than a million-and-a-half index CRS-related hospitalizations (mean age, 64.37±13.30 years). Patients had CKD stage I to II (6%), CKD stage III to IV (72.6%), and CKD stage V or higher (21.3%). Patients with CKD stage V and higher, compared with the other subgroups, had the highest mortality (7.6% vs 5.73%; P <.001).

The overall CRS-related 30-day readmission was 22.7%. Of that, patients with CKD stage V and higher represented 39.89%, patients with CKD stage III to IV represented 20.05%, and patients with CKD stage I to II represented 12.99%. The 30-day readmission primary etiology was cardiovascular among all subgroups (stage I-II, 54.2%; stage III-IV, 54.6%; stage V-and-more, 41.8%).

They noted that patients with CKD stage III to IV, compared with the other subgroups, more commonly had acute kidney injury (AKI) (55.9% vs 43.7%; P <.001). The second major complication, respiratory failure, was more common among patients with CKD stage V and higher compared with the other subgroups (32.5% vs 30.0%; P <.001).

They observed non-ST elevation myocardial infarction in 17.4% of patients with CKD stage V and higher vs 16.2% in the other subgroups (P <.001). They noted pulmonary hypertension in 17.9% of patients with CKD stage III to IV vs 16.3% in other subgroups (P <.001).

Study limitations include the retrospective observational design and possible inaccuracies in ICD-10 codes. There is also a lack of data related to medications, examinations, diagnostic imaging and laboratory results.

“CRS among HFrEF is associated with significant 30-day readmission rates, contributing to increased healthcare expenditures within [the] US,” the study authors wrote. “Nearly one third of the patients with CKD stage V-and-more required re-hospitalizations within 30-days of discharge.” This subgroup, compared with the other subgroups, had higher rates of GI bleeding, AKI requiring dialysis, pulmonary embolisms, respiratory failure, and all-cause mortality.