Influence of renal function on the effects of early revascularization in non-ST-elevation myocardial infarction: data from the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART).
BACKGROUND
It is unknown whether patients with non-ST-elevation myocardial infarction derive a similar benefit from an early invasive therapy at different levels of renal function.


RESULTS
A total of 23 262 consecutive non-ST-elevation myocardial infarction patients <or=80 years old were included in a nationwide coronary care unit register between 2003 and 2006. Glomerular filtration rate (eGFR) was estimated with the Modification of Diet in Renal Disease Study formula. Patients were divided into medically or invasively treated groups if revascularized within 14 days of admission. A propensity score for the likelihood of invasive therapy was calculated. A Cox regression model with adjustment for propensity score and discharge medication was used to assess the association between early revascularization and 1-year mortality across renal function stages. There was a gradient, with significantly fewer patients treated invasively with declining renal function: eGFR >or=90 mL . min(-1) . 1.73 m(-2), 62%; eGFR 60 to 89 mL . min(-1) . 1.73 m(-2), 55%; eGFR 30 to 59 mL . min(-1) . 1.73 m(-2), 36%; eGFR 15 to 29 mL . min(-1) . 1.73 m(-2), 14%; and eGFR <15 mL . min(-1) . 1.73 m(-2)/dialysis, 15% (P<0.001). After adjustment, the overall 1-year mortality was 36% lower (hazard ratio 0.64, 95% confidence interval 0.56 to 0.73, P<0.001) with an invasive strategy. The magnitude of survival difference was similar in normal-to-moderate renal function groups. The lower mortality observed with invasive therapy declined with lower renal function, with no difference in mortality in patients with kidney failure (eGFR <15 mL . min(-1) . 1.73 m(-2)) or in those receiving dialysis (hazard ratio 1.61, 95% confidence interval 0.84 to 3.09, P=0.15).


CONCLUSIONS
Early invasive therapy is associated with greater 1-year survival in patients with non-ST-elevation myocardial infarction and mild-to-moderate renal insufficiency, but the benefit declines with lower renal function, and is less certain in those with renal failure or on dialysis.
Szummer
Karolina
K
Department of Medicine, Section of Cardiology, Karolinska University Hospital, Huddinge, Institution of Medicine (H7), Huddinge, Karolinska Institutet, 141 86 Stockholm, Sweden. karolina.szummer@karolinska.se
Lundman
Pia
P
Jacobson
Stefan H
SH
Schön
Staffan
S
Lindbäck
Johan
J
Stenestrand
Ulf
U
Wallentin
Lars
L
Jernberg
Tomas
T
D000368:Aged; D004562:Electrocardiography; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000503:physiopathology*; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology* / Q000601:surgery*; D009204:Myocardial Revascularization; D018579:Patient Selection; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D006435:Renal Dialysis; D051437:Renal Insufficiency / Q000150:complications / Q000628:therapy; D013997:Time Factors