Long-term cardiovascular outcomes in patients with chronic kidney disease undergoing coronary artery bypass graft surgery for acute coronary syndromes

Background

Patients with chronic kidney disease have an increased risk of death after myocardial infarction, coronary artery bypass graft surgery (CABG), and percutaneous coronary intervention. We sought to describe the association between chronic kidney disease and long‐term cardiovascular outcomes and death in patients who underwent CABG for acute coronary syndromes.

Methods and Results

All patients (N=12 956) from the Swedish Web System for Enhancement and Development of Evidence‐Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry who underwent CABG for acute coronary syndromes in Sweden between 2000 and 2008 with complete information on preoperative serum creatinine values were included. Estimated glomerular filtration rates (eGFRs) were obtained, and hazard ratios with 95% CIs were calculated for the composite end point of myocardial infarction, heart failure, stroke, or death in relation to eGFR. During a mean follow‐up of 3.5 years, there were in total 2844 (22%) cardiovascular events and 1340 (10%) deaths. In patients with eGFR >60 mL/min per 1.73 m², 45 to 60 mL/min per 1.73 m², and 15 to 45 mL/min per 1.73 m², there were 2896 (28%), 882 (43%), and 407 (61%) cardiovascular events or deaths, respectively. Hazard ratios with 95% CIs for death or any cardiovascular event in patients with eGFR 45 to 60 mL/min per 1.73 m², and 15 to 45 mL/min per 1.73 m² were 1.07 (0.98 to 1.15) and 1.36 (1.22 to 1.53) respectively, after multivariable adjustment. The corresponding figures for any cardiovascular event were 1.08 (0.98 to 1.19), and 1.24 (1.08 to 1.43).

Conclusions

Severe, but not moderate, renal dysfunction was independently associated with an increased risk of long‐term cardiovascular events and death in patients undergoing CABG for acute coronary syndromes.

Ticagrelor versus clopidogrel in acute coronary syndromes in relation to renal function: results from the Platelet Inhibition and Patient Outcomes (PLATO) trial

BACKGROUND

Reduced renal function is associated with a poorer prognosis and increased bleeding risk in patients with acute coronary syndromes and may therefore alter the risk-benefit ratio with antiplatelet therapies. In the Platelet Inhibition and Patient Outcomes (PLATO) trial, ticagrelor compared with clopidogrel reduced the primary composite end point of cardiovascular death, myocardial infarction, and stroke at 12 months but with similar major bleeding rates.

METHODS AND RESULTS

Central laboratory serum creatinine levels were available in 15 202 (81.9%) acute coronary syndrome patients at baseline, and creatinine clearance, estimated by the Cockcroft Gault equation, was calculated. In patients with chronic kidney disease (creatinine clearance <60 mL/min; n=3237), ticagrelor versus clopidogrel significantly reduced the primary end point to 17.3% from 22.0% (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.65 to 0.90) with an absolute risk reduction greater than that of patients with normal renal function (n=11 965): 7.9% versus 8.9% (HR, 0.90; 95% CI, 0.79 to 1.02). In patients with chronic kidney disease, ticagrelor reduced total mortality (10.0% versus 14.0%; HR, 0.72; 95% CI, 0.58 to 0.89). Major bleeding rates, fatal bleedings, and non-coronary bypass-related major bleedings were not significantly different between the 2 randomized groups (15.1% versus 14.3%; HR, 1.07; 95% CI, 0.88 to 1.30; 0.34% versus 0.77%; HR, 0.48; 95% CI, 0.15 to 1.54; and 8.5% versus 7.3%; HR, 1.28; 95% CI, 0.97 to 1.68). The interactions between creatinine clearance and randomized treatment on any of the outcome variables were nonsignificant.

CONCLUSIONS

In acute coronary syndrome patients with chronic kidney disease, ticagrelor compared with clopidogrel significantly reduces ischemic end points and mortality without a significant increase in major bleeding but with numerically more non-procedure-related bleeding.

CLINICAL TRIAL REGISTRATION

URL:http://www.clinicatrials.gov. Unique identifier: NCT00391872.

Relation between renal function, presentation, use of therapies and in-hospital complications in acute coronary syndrome: data from the SWEDEHEART register

OBJECTIVE

To examine clinical characteristics, presenting symptoms, use of therapy and in-hospital complications in relation to renal function in patients with myocardial infarction (MI).

DESIGN

Observational study.

SETTING

Nationwide coronary care unit registry between 2003-2006 in Sweden.

SUBJECTS

Consecutive MI patients with available creatinine (n = 57,477).

RESULTS

Glomerular filtration rate was estimated with the Modification of Diet in Renal Disease Study formula. With declining renal function patients were older, had more co-morbidities and more often used cardio-protective medication on admission. Compared to patients with normal renal function, fewer with renal failure presented with chest pain (90% vs. 67%, P < 0.001), Killip I (89% vs. 58%, P < 0.001) and ST-elevation myocardial infarction (STEMI) (41% vs. 22%, P < 0.001). In a logistic regression model lower renal function was independently associated with a less frequent use of anticoagulant and revascularization in non-ST-elevation MI. The likelihood of receiving reperfusion therapy for STEMI was similar in patients with normal-to-moderate renal dysfunction, but decreased in severe renal dysfunction or renal failure. Reperfusion therapy shifted from primary percutaneous coronary intervention in 71% of patients with normal renal function to fibrinolysis in 58% of those with renal failure. Renal function was associated with a higher rate of complications and an exponential increase in in-hospital mortality from 2.5% to 24.2% across the renal function groups.

CONCLUSION

Renal insufficiency influences the presentation and reduces the likelihood of receiving treatment according to current guidelines. Short-term prognosis remains poor.

Cockcroft-Gault is better than the Modification of Diet in Renal Disease study formula at predicting outcome after a 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

The aim was to examine whether the Modification of Diet in Renal Disease (MDRD) or the Cockcroft-Gault (CG) formula is better at predicting prognosis in myocardial infarction (MI) patients.

METHODS

All consecutive MI patients entered in a nationwide registry between 2003 and 2006 with glomerular filtration rate (eGFR) estimated by both the MDRD and CG formula (N = 36,137) were analyzed.

RESULTS

Cockcroft-Gault classified a larger proportion of patients as having at least a moderate (39.8% vs 31.1%, P < .001) or at least a severe renal dysfunction (7.6% vs 4.4%, P < .001) compared with the MDRD. The largest difference between the estimations was seen when patients were divided according to gender, age, and weight, where CG estimated a lower eGFR in women, the elderly, and those with low body weight. In a receiver operating characteristic analysis, CG had a stronger association to 1-year mortality (area under the curve 0.78, 95% CI 0.77-0.79) than MDRD (area under the curve 0.73, 95% CI 0.72-0.74). Within each renal function stage classified with the MDRD, there were patients identified with the CG as having both a worse renal function and a higher mortality. After multivariable adjustment, CG predicted 1-year mortality better than the MDRD (renal failure vs normal renal function: hazard ratio 3.00, 95% CI 2.42-3.71 with the CG; hazard ratio 2.56, 95% CI 2.10-3.11 with the MDRD).

CONCLUSION

Cockcroft-Gault is better than the MDRD equation at predicting mortality after a MI. This is mainly explained by differences in the coefficients and variables included in the eGFR equations, and less to differences in various subgroups of patients.

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.

METHODS AND 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.