N-terminal probrain natriuretic peptide predicts adverse outcomes in acute-myocardial infarction even with preserved left ventricular ejection fraction.
BACKGROUND
Risk stratification of patients with acute myocardial infarction is based on various clinical, biochemical or electrocardiographic parameters. There is emerging evidence that N-terminal probrain natriuretic peptides (NT-proBNP) possess characteristics of an ideal biomarker. In this study we looked into the role of NT-proBNP in risk stratification and prediction of short-term events in patients presenting with acute myocardial infarction (MI) and having preserved left ventricular functions as assessed by ejection fraction (EF) on echocardiography.


RESULTS
Of a total of 250 consecutive patients admitted with a diagnosis of acute ST segment elevation myocardial infarction, 84 patients were found to have ejection fraction greater than 50% (44 with anterior MI, 40 with inferior MI. Serum NT-proBNP was measured using electrochemiluminiscence assay (Roche). On two-dimensional echocardiography, modified Simpson's technique was used to measure the EF. Follow-up at day 30 included a two-dimensional echocardiography and assessment for worsening heart failure, recurrent ischemia, and repeat hospitalization. Death due to cardiovascular cause by 30 days was also noted. The mean value of NT-proBNP for those having EF over 50% was 1542.38 + 4649.12 pg/ml. For the purpose of a dichotomous analysis, the median value was determined (907.5 pg/ml). In patients having NT-proBNP above median, the Killip class was expectedly higher 1.62 + 0.21 vs 1.0 + 0.12 ( p< 0.05) and the thrombolysis in myocardial infarction scores were worse (4.77 + 1.56 vs 2.71 + 1.11, p < 0.05). The ejection fraction was similar (59.72 + 8.8 vs 58.76 + 6.9, p= NS) in the two groups. At 30 days followup, patients having NT-proBNP above median showed a further decline in the Killip class and EF. The clinical outcomes (composite of recurrent ischemia, worsening heart failure and repeat hospitalization) were also worse in this group ( p< 0.05).


CONCLUSIONS
In patients with apparently normal ejection fraction and without left ventricular dysfunction, a higher NT-proBNP level would suggest poorer short-term clinical outcomes and would require a more aggressive treatment strategy.
Puri
Aniket
A
Department of Cardiology, King George Medical University, Lucknow. aniket1@sancharnet.in
Narain
Varun S
VS
Mehrotra
Sanjay
S
Dwivedi
Sudhanshu K
SK
Saran
Ram K
RK
Puri
Vijay K
VK
D000368:Aged; D015415:Biomarkers / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D018570:Risk Assessment; D013318:Stroke Volume; D014463:Ultrasonography; D016277:Ventricular Function, Left
D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain