Mapping the complexity of care in patients with heart disease living with chronic kidney disease.

INTRODUCTION: Patients with myocardial infarction (MI) or heart failure (HF) often have concomitant chronic kidney disease (CKD). These patients are perceived as 'complex', but empirical evidence quantifying this complexity or exploring the diseases and problems they experience is scarce. We aimed here to comprehensively characterize the complexity of care among patients with MI/HF across the spectrum of CKD severity and to identify frequent longitudinal disease accrual trajectories associated with all-cause mortality. METHODS: Retrospective cohort of 29 901 adults surviving an incident MI/HF hospitalization from the Stockholm CREAtinine Measurements (SCREAM, 2006-2021) project. KDIGO CKD stages were classified as no CKD, mild CKD, or moderate-to-severe CKD using plasma creatinine and urinary albumin at hospital admission. Care complexity was evaluated through multidimensional indicators encompassing comorbid conditions, treatments, healthcare use, and mortality. Process mining identified longitudinal trajectories of disease accrual and associated mortality risks. RESULTS: Increasing CKD severity was associated with greater comorbidities, polypharmacy, healthcare use, and higher observed rate of recurrent MI/HF and death. We identified 8927 hospitalizations and 20 805 outpatient disease trajectories during follow-up. CKD patients more often accumulated multiple circulatory diagnoses, significantly increasing mortality hazards compared with those without CKD. Trajectories involving progression to endocrine/metabolic, respiratory, neoplastic, and genitourinary diseases became more frequent with advancing CKD and were strongly associated with death. CONCLUSIONS: Among MI/HF survivors, those with CKD are the most complex and resource-demanding. We identified key comorbidity patterns that provide opportunities for earlier, targeted interventions-particularly addressing endocrine, respiratory, and neoplastic complications-to reduce their adverse outcomes and premature mortality.