A Comparison of Early Echocardiographic Findings in Patients having First Acute Myocardial Infarction with or without Pre-Infarct Angina

Abstract

Background: Acute myocardial infarction (AMI) is the most common cause of morbidity and
mortality. In order to reduce myocardial infarct size, a new technique i.e. ischemic preconditioning has evolved. The brief periods of ischemia followed by reperfusion appear to precondition the heart and make it more resistant to a subsequent longer period of ischemia. Preconditioning is defined as “a rapid, adaptive response to a brief ischemic insult, which slows the
rate of cell death during a subsequent, prolonged period of ischemia.”
Material & Methods: Acomparative study was conducted to identify the patients of AMI with or
without pre-infarction angina, to find out the differences in their in-hospital course and to assess
the prognostic value of pre-infarction angina in first episode of AMI during hospital stay.
Results: Twenty-five patients with (Group A) and 25 patients without (Group B) pre-infarction
angina were compared for their in-hospital course. Mean age ± SD in Group A was 55 ± 7 years
and in Group B 54 ± 8 years. There were 18 (72%) males and 7 (28%) females in Group A, and 17
(68%) males and 8 (32%) females in Group B. As far as the baseline risk factors in two groups
were concerned, 5 vs 7 patients had diabetes mellitus, 7 vs 8 had hypertension, 16 (64%) vs 13
(52%) were smoker, 3 vs 4 had obesity, 4 vs 5 had family history of IHD and 5 vs 6 had
hyperlipidemia in Group A and Group B respectively. Regarding the intake of anti-anginal
medication like calcium channel blockers, beta-blockers and nitrates in the two groups, there
were more patients in Group A as compared to B who were taking them (p<0.05). Similarly there
were also 10 (40%) vs 2 patients in Group Aand B respectively who were taking aspirin (p<0.05).
In-hospital complications like cardiogenic shock, CCF, LVF, RVF, recurrent ischemic pain, infarct
extension and rhythm abnormalities were more in Group B as compared to Group A (p<0.05).
When echocardiography was performed, the data showed that the ejection fraction percentage
(mean ± SD) in Group A was 55% ± 7.8 versus 44% ± 7.9 in Group B (p<0.001). There were 3 in
Group A vs 13 patients in Group B who had developed aneurysm (p<0.05), 2 in Group A vs 1 in
Group B who had papillary muscle rupture, 1 in Group Avs 5 in Group B who developed VSD and
4 in Group Avs 10 in Group B who had clot in left ventricle. While in-hospital mortality between two
groups was observed, there was only 1 in-hospital death in Group A vs 6 (24%) in Group B
(p<0.05).
Conclusion: The presence of pre-infarction angina had a favorable effect on in-hospital course
after AMI i.e. a lower incidence of in-hospital mortality, a lower incidence of in-hospital
complications, development of significantly smaller infarct size with a higher ejection fraction and
a lower incidence of aneurysmal formation