Background: Acute coronary syndrome (ACS) accounts for 2.43 million hospital discharges per year. Patients presenting with ACS represent a heterogeneous group with regard to the severity of coronary atherosclerosis, recurrence and prognosis. Major advances in the management of ACS have emphasized the importance of earlier identification of higher risk patients among whom aggressive approaches to revascularization might improve outcome. The study therefore can provide data regarding the incidence and factors associated with recurrent ischemia.
Method: This was a case control study that determined the factors associated with recurrent Acute Coronary Syndrome in patients admitted at the Philippine Heart Center between January 2009 up to December 2014. Patients admitted for first time MI were assigned to the control group. On the other hand, patients admitted for recurrent MI were assigned to the case group. Medical chart review was done to identify predisposing risk factors associated with recurrent MI. Homogeneity of characteristics between two groups was tested using independent t-test for quantitative variables or Fisher's exact test for qualitative variables. Predictors of recurrent MI were then determined using Logistic regression analysis. The level of significance (α) was set at 0.05.
Results: Patients with recurrent MI had a mean age of 70 years while patients diagnosed with MI for the first time had a mean age of 64 years. Patients who presented with recurrent MI had a greater incidence of the following: Diabetes Mellitus (p value 0.000); Congestive Heart Failure (p value 0.003); Previous PCI (p value 0.000); and Previous CABG (p value 0.000). Patients with recurrent MI were noted to have mean serum creatinine of 0.16 compared to that of control patients who had mean serum creatinine of 0.11 (p value 0.000). In addition, patients with recurrent MI were noted to have a mean TIMI score of 6.57 while the control group only had a mean TIMI score of 3.81 (p value 0.0062). GRACE score (p value 0.0236) was likewise higher, with the recurrent MI group having a mean score of 145 compared to the mean score of 135 for the control group. The presence of multivessel disease (p value of 0.003) with involvement of the left anterior descending artery (p value 0.000) and stent implantation (p value 0.0006) were significantly associated with recurrent MI.
Conclusion: Results of this study concurred with findings noted in previous studies which identified a history previous MI, the presence of Diabetes Mellitus, and increased age, among others, as significant risk factors associated with recurrent MI. Diagnostic catheterization likewise revealed that recurrent MI was significantly associated with multivessel involvement and with involvement of the left anterior descending artery.