Myocardial Infarction; New Onset Heart Failure after Mi. Its Frequency and Factors Contributing It

.. Objectives: To determine the frequency of new onset heart failure after acute myocardial infarction and factors contributing it. Methods: A total of 228 patients were studied for occurrence of new onset clinical heart failure within24 hours after admission with an acute Myocardial Infarction. Clinical parameters were used to diagnose heart failure. Various risk factors were analyzed which contributed to occurrence of heart failure after MI. Patients undergoing primary angioplasty were not included into this study as medical thrombolysis was the most common mode of therapy (in >90% of patients). Results: Among the 228 patients studied 77.2 %( 176) were males and 22.8 %(52) were females. Mean age of the population was 56.3(±12.1) years. Women were relatively older on presentation as compared to men (mean age 58.9±10.9yr vs 55.5±12.3yr). Similarly mean age for NSTEMI was higher as compared to STEMI (58.59±11.1 vs 54.2±12.6yr.). A total of36.8 %( 84) patients exhibited clinical signs of heart failure within24 hours of their admission. These patients tend to be older than patients without HF (mean age 60±11years vs 54±12 years). Females after MI showed a greater frequency for going into HF as compared to males (42.3% vs 35.2% respectively). Now regarding the association of HF with various factors it was seen that, having a previous history of MI was found to be the strongest factor associated with occurrence of HF, with HF being nearly three times more common in these patients (i.e. 73% vs 26.1%, p value < 0.05). The current type of MI on presentation also showed a direct relationship with HF, being highest in patients with NSTEMI (i.e. up to 50 %) followed by AWMI (35.5%) and lowest in inferior wall MI (p value < 0.05). Diabetes, hypertension and smoking also showed a higher but statistically nonsignificant relationship with HF development (41.2% vs 34.3%, 41% vs 32.2% and 44% vs 32% respectively p value > 0.05). The blood pressure on presentation however was significantly associated with HF in these patients. Patients having high BP (> 140/80) on presentation depicted an overall higher incidence of HF as compared to patients having BP equal to or less than 140/80 (45.2% vs 31.3% p value < 0.05). Conclusion: Heart failure is a fairly common entity after acute MI, being the commonest in patients suffering an NSTEMI. Previous history of an MI showed to be the strongest coexisting factor associated with HF.