Multimorbidity and medication complexity: new challenges in heart transplantation

INTRODUCTION: Multimorbidity and therapeutic complexity are a recognized problem in the heart transplant (HTx) population. However, little is known about how best to quantify this complexity or the strategies that could reduce its burden. METHODS: This single-center, observational study included adult heart transplant recipients (HTxR) >1.5 years from transplant. We assessed multimorbidity (>2 comorbidities) and the patient-level Medication Regimen Complexity Index Spanish version (pMRCI-S) score. We also analyzed the independent predictors of pMRCI-S and the impact of the index score on specific clinical variables. RESULTS: We included 135 chronic-stage HTxR. Comorbidities significantly increased after HTx (6 ± 3 vs 2 ± 2, P-value < .001). Patients took 12 ± 3 chronic drugs/d, 58% of them to treat comorbidities. The mean total pMRCI-S score was 42 ± 11, higher than in several other chronic diseases. The medication category drugs to treat comorbidities predicted a higher total pMRCI-S score (OR = 3.12, 95% CI 2.8-3.43, P-value < .001). Therapeutic complexity after HTx had an impact on solid malignancies (OR = 1.1, 95% CI 1.02-1.18, P-value = .02) and renal function (OR=-0.81, 95% CI -1.21-(-0.42), P-value < .001). CONCLUSIONS: The multimorbidity and pMRCI-S scores obtained in HTx population were worrisomely high. The pMRCI score is a sensitive method that allows identification of the factors determining therapeutic complexity after HTx and selection of strategies to reduce pMRCI-S values.