Excess weight at time of presentation of myocardial infarction is associated with lower initial mortality risks but higher long-term risks including recurrent re-infarction and cardiac death.
OBJECTIVE
To evaluate the influence of elevated body mass index (BMI) on short- and long-term survival following acute myocardial infarction (AMI).


BACKGROUND
Recent studies suggest an obesity survival paradox in individuals undergoing percutaneous coronary intervention with better 30-day and 1-year outcomes in obese relative to normal weight patients. We tested a similar obesity paradox hypothesis following acute myocardial infarction.


METHODS
Short- and long-term all-cause mortality, and risk of recurrent AMI were evaluated according to BMI status in 894 consecutive survivors of AMI <80 years of age admitted to the Mayo Clinic Coronary Care Unit between January 1, 1988 and April 16, 2001. Normal weight, overweight and obesity were defined as BMI <25, 25-29.9, and >30 kg/m(2), respectively.


RESULTS
Overall mortality following hospital discharge was significantly lower in overweight and obese patients and was mostly attributable to lower 6-month mortality (adjusted HR = 0.47, P = 0.01 for BMI >25 kg/m(2)) relative to normal weight patients, while long-term mortality among 6-month survivors was similar in all 3 groups. The risk of recurrent AMI was higher in patients with BMI >25 kg/m(2) (adjusted HR = 2.30, P = 0.01). Overweight and obese patients were significantly more likely to die from cardiac rather than non-cardiac causes (P < 0.01).


CONCLUSIONS
Following AMI, overweight and obese individuals although paradoxically protected from short-term death have a long-term mortality risk that is similar to normal weight individuals. Younger age at the time of initial infarction and fewer non-cardiovascular comorbidities presumably explain the short-lived obesity survival paradox following myocardial infarction.
Nigam
Anil
A
Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
Wright
R Scott
RS
Allison
Thomas G
TG
Williams
Brent A
BA
Kopecky
Stephen L
SL
Reeder
Guy S
GS
Murphy
Joseph G
JG
Jaffe
Allan S
AS
D000368:Aged; D015992:Body Mass Index; D016022:Case-Control Studies; D003643:Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000517:prevention & control*; D009765:Obesity / Q000150:complications* / Q000401:mortality; D050177:Overweight; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors