Estimation of functional reserves of the body and risk of cardiovascular events in patients with myocardial infarction with comorbid pathology undergoing rehabilitation

Background
Cardiovascular diseases are the leading cause of death worldwide. In Ukraine, cardiovascular mortality is 66.7%.

Material and methods
We examined 371 patients with myocardial infarction (MI) with comorbid pathology who had undergone 90 days of rehabilitation. We studied the possibility of quantitative estimation of comorbid pathology, the condition of functional reserves in patients with MI, their connection with clinical markers of reduced exercise tolerance and comorbidity index.

Results
We established close correlations between the six-minute walk tests conducted on the 10th, 30th and 90th days of rehabilitation (6MWT10, 6MWT30 and 6MWT90) with age of patients (r6MWT10 = -0.199; r6MWT30 = -0.287; r6MWT90 = -0.410 P < 0.05), SpO₂ (r6MWT10 = -0.399; r6MWT30 = -0.265; r6MWT90 = -0.248; P < 0.05), left ventricular ejection fraction (r6MWT10 = 0.706; r6MWT30 = -0.670; r6MWT90 = -0.583; P < 0.0001), troponin levels (r6MWT10 = -0.210; r6MWT30 = -0.312; P < 0.05); creatinine (r6MWT10 = -0.148; P < 0,05;) and Charlson comorbidity index (r6MWT10 = -0.323; r6MWT30 = -0.398; r6MWT90 = -0.427; P < 0.0001).

Conclusions
Markers of reduced exercise tolerance in patients with IM were age, SpO₂, ejection fraction, levels of troponin, creatinine, lymphocytes, Charlson comorbidity index.