Prognostic impact of multimorbidity in patients with type 2 diabetes and ST-elevation myocardial infarction

INTRODUCTION: There is an increasing body of evidence on the clinical importance of multimorbidity, which is defined as the coexistence of two or more chronic conditions. Type 2 diabetes (T2DM) is one of the most frequent chronic conditions. Most adults with type 2 diabetes have at least 1 coexisting chronic condition and approximately 40% have 3 or more. Prior studies have suggested that cardiovascular (CVD) and non-CVD comorbid conditions yield worse outcomes in patients hospitalized with ST-elevation myocardial infarction (STEMI). It is unclear, however, the extent to which multimorbidity has a cumulative effect on long-term risk. Therefore we have set out to determine the prognostic value of multiple comorbidity on long-term outcomes in this population of patients. METHODS: A total of 277 patients with T2DM and STEMI undergoing primary percutaneous coronary intervention (PCI) were enrolled. Based on the number of comorbidities the study population was divided into two groups: group 1 (N=58) with ≤ 1 comorbidity and group 2 (N=219) with ≥ 2 comorbidities. RESULTS: Comorbid conditions were prevalent among study participants (Figure 1). The median number of comorbidities was three. 15.9% of patients had one comorbidity and 22.0%, 34.3%, and 22.7% of patients had two, three or at least four comorbid conditions respectively. A majority of patients had at least one CVD comorbidity (6.1% of patients had none), whereas 53.1% of patients did not have any non-CVD comorbidity. During hospitalization 3 out of 58 patients (5.2%) died in group 1 and 25 of 219 patients (11.4%) died in group 2. The number of comorbid conditions was not an independent predictor of in-hospital death. During 12-month follow-up, 5 of 58 patients (8.6%) and 42 of 219 patients (19.9%) died, respectively in group 1 and 2 (P=0.05). The number of comorbid conditions proved in ROC analysis that for 12-month mortality, the prognostic value was modest, but for 12-month acute coronary syndromes the prognostic value was good. Increase in the number of comorbid conditions by one was associated with a 15% increase in the relative risk of 12-month mortality and a 41% increase in the relative risk of 12-month acute coronary syndromes (ACS). CONCLUSIONS: Comorbid conditions are highly prevalent among these groups of patients. Majority of patients have at least 2 other cardiovascular comorbidities and one or two non-cardiovascular comorbidities. In terms of long-term follow-up, multimorbidity was associated with worse outcomes. The risk of both long-term mortality and ACS increased with the increasing number of comorbidities. In summary, our findings highlight the importance of indentifying patients with multimorbidity. This, in turn, could allow for provision of better care to these high-risk and complex group of patients.