The five-year survival of patients with various components of metabolic syndrome after Q-myocardial infarction

Abstract

Introduction. According to clinical studies the presence of metabolic syndrome contributes significant increase in the level of early hospital mortality and impairs remote prognosis and survival of patients after myocardial infarction [5,6].The major danger represents summation of the various components of metabolic syndrome, as they provide a synergistic effect and form the pathogenetic cycle that leads to future fatal and non-fatal cardiovascular events [2]. Today the impact of the components of the metabolic syndrome on survival of patients after myocardial infarction has not been studied yet.

Objective: To investigate the survival of patients with various components of the metabolic syndrome during five years after undergone Q-myocardial infarction.

Materials and Methods: The study included 317 patients with Q-MI aged 40 to 85 years (mean age 62,5 ± 0,90 years), male 48.26% (153 people), female 51.74% (164 people ): 256 patients with metabolic syndrome (mean age 64,55 ± 0,49 years), male 55.86% (143 people), female 44.14% (113 people), 61 patients without metabolic syndrome (comparison group) (mean age 62,96 ± 1,30 years), male 65.57% (40 people), female 34.43% (21 people).

For the purpose of the study, patients with metabolic syndrome were divided into groups:

Group 1 - 95 patients with abdominal obesity, hypertension, impaired carbohydrate metabolism and dyslipoproteinemia (four-component metabolic syndrome), mean age 64,28 ± 1,03 years 56 (58.95%) male, 39 (41.01%) female;

Group 2 - 74 patients with abdominal obesity, hypertension, dyslipoproteinemia without carbohydrate metabolism, mean age 64,41 ± 1,03 years, 46 (62.16%) male, 28 (37.84%) female;

Group 3 - 87 patients with type 2 diabetes, hypertension, dyslipoproteinemia without obesity (BMI 25-30 kg/m2), mean age 64,98 ± 0,93 years, 48 (55.17%) male, 39 (44.83%) female.

After discharge from hospital, the patients performed outpatient supervision for 5 years from the date of enrollment. Analyzed endpoint is - death and the combined end point "death / nonfatal MI / hospitalization for NA / coronary intervention." Upon reaching the end point of the study, patients were excluded from observation.

Data obtained from the survey have been processed by methods of variation statistics using application package «Statistica» (version 6.0, Stat Soft Ins, United States, № license AXXR712D833214FAN5). To analyze the function of survival the method of multiple assessments Kaplan-Meier has been used. To assess the reliability between groups non-parametric test Uyilkoksona-Hehana, F-Cox test, test-Cox Mantela have been used.

Results: After 5 years, 73 deaths (28.52%) patients who underwent Q-MI at the background of MS, and 8 (13.11%) patients with myocardial infarction without Q-MS. The observed difference between the groups in terms of survival (Gehan's Wilcoxon Test - p <0,05; Cox's F-Test - p <0,05; Log-Rank Test - p <0,01, Sox-Mantel Test - p <0,05 ) for five years. As shown from the graph, statistically significant differences begin to appear after six-month period and reach a maximum after 4 years of observation. The development of coronary events (combined end point "death / nonfatal MI / hospitalization for NA / coronary intervention") at 5 years has been observed in 119 (46.48%) patients with Q-MI with MS and in 12 (19.67%) patients with myocardial infarction without Q-MS. A statistically significant difference in the development of the combined end point among patients with myocardial infarction with Q-MS and without MS (Gehan'sWilcoxon Test - p <0,01; Cox's F-Test - p <0,01; Log-Rank Test - p <0,001 , Sox-Mantel Test - p <0,001) has been observed.

The mortality rate within five years after myocardial infarction criteria for Cox-Mantela probably prevailed in patients with multi-component metabolic syndrome group 1 (p <0.01) and in patients with metabolic syndrome 3 groups of existing diabetes (p <0 , 05) compared with patients without metabolic syndrome. There was probable difference for the development of a combined end point "death / nonfatal MI / hospitalization for NA / coronary intervention" between patients with MS 1-3 IM groups and without MS.

Conclusions:

1. The presence of concomitant metabolic syndrome negatively affects remote prognosis and is associated with an increase in cardiovascular mortality within five years after undergone Q-MI at 2.2 times.
2. The incidence of cardiovascular death and the combined end point "death / nonfatal MI / hospitalization for NA / coronary intervention," the largest groups of patients with multi-component metabolic syndrome and present diabetes have been observed.