Chronic kidney disease, mortality, and treatment strategies among patients with clinically significant coronary artery disease

Comparison of the relation between renal impairment, angiographic coronary artery disease, and long-term mortality in women versus men

Mild to moderate renal impairment has recently been associated with increased cardiovascular mortality. However, gender differences in the association of mild to moderate renal impairment with the presence of angiographic coronary artery disease and long-term mortality remain unknown. We examined a prospective cohort of consecutive patients who underwent coronary angiography from the ACRE study in the Royal Hospitals Trust (London, United Kingdom) with referral from 5 contiguous health authorities. Among 1,609 patients (465 women) who had angiographic and serum creatinine measurements at baseline, renal impairment at modification of diet in renal disease glomerular filtration rates of 45 to 59, 30 to 44, and <30 ml/min/1.73 m(2) was more common in women than in men and was significantly associated with the presence of angiographic coronary artery disease in women but not in men. At each level of glomerular filtration rate, multivariate adjusted hazard ratios of 7-year all-cause mortality for women compared with men were higher: 2.64 (95% confidence intervals [CI] 1.21 to 5.73) versus 1.34 (95% CI 0.995 to 1.79); 2.62 (95% CI 1.12 to 16.12) versus 2.35 (95% CI 1.60 to 3.43); and 10.42 (95% CI 3.97 to 27.39) versus 4.77 (95% CI 2.95 to 7.70), respectively. Similar patterns were observed in cardiovascular and coronary deaths. In conclusion, mild to moderate renal impairment may be a marker for unmeasured proatherogenic factors for women only, and women may bear a greater mortality burden that is attributable to renal impairment compared with men. Gender may influence the prognostic effect of renal impairment in coronary disease.

Impact of renal dysfunction on outcomes of coronary artery bypass surgery: results from the Society of Thoracic Surgeons National Adult Cardiac Database

BACKGROUND

Although patients with end-stage renal disease are known to be at high risk for mortality after coronary artery bypass graft (CABG) surgery, the impact of lesser degrees of renal impairment has not been well studied. The purpose of this study was to compare outcomes in patients undergoing CABG with a range from normal renal function to dependence on dialysis.

METHODS AND RESULTS

We reviewed 483,914 patients receiving isolated CABG from July 2000 to December 2003, using the Society of Thoracic Surgeons National Adult Cardiac Database. Glomerular filtration rate (GFR) was estimated for patients with the use of the Modification of Diet in Renal Disease study formula. Multivariable logistic regression was used to determine the association of GFR with operative mortality and morbidities (stroke, reoperation, deep sternal infection, ventilation >48 hours, postoperative stay >2 weeks) after adjustment for 27 other known clinical risk factors. Preoperative renal dysfunction (RD) was common among CABG patients, with 51% having mild RD (GFR 60 to 90 mL/min per 1.73 m2, excludes dialysis), 24% moderate RD (GFR 30 to 59 mL/min per 1.73 m2, excludes dialysis), 2% severe RD (GFR <30 mL/min per 1.73 m2, excludes dialysis), and 1.5% requiring dialysis. Operative mortality rose inversely with declining renal function, from 1.3% for those with normal renal function to 9.3% for patients with severe RD not on dialysis and 9.0% for those who were dialysis dependent. After adjustment for other covariates, preoperative GFR was one of the most powerful predictors of operative mortality and morbidities.

CONCLUSIONS

Preoperative RD is common in the CABG population and carries important prognostic importance. Assessment of preoperative renal function should be incorporated into clinical risk assessment and prediction models.

Coronary artery disease and peripheral vascular disease in chronic kidney disease: an epidemiological perspective

The enormous burden of CAD and PVD inpatients who have CKD contributes substantially to increased morbidity and mortality. The increased risk of vascular disease observed in CKD patients is likely to be multifactorial, with contributions from traditional and nontraditional cardiovascular factors. Given the overwhelming evidence on the known benefits of cardioprotective medications, their underuse remains puzzling in a population at enormous risk. During the past 5 years, the research community and national interest groups have made significant progress in organizing a concerted approach to improve the management of patients who have CKD and vascular disease. Much work remains to be done. The development of national guidelines in the management of these patients at high risk for future cardiovascular events will be a welcome step. The evaluation of multitargeted interventions for reduction of cardiovascular risk through randomized clinical trials is desperately needed. Finally, the low use of known cardioprotective strategies in this high-risk group is a serious issue and warrants immediate attention at local and national levels.

Outcomes of contrast-induced nephropathy: Experience in patients undergoing cardiovascular intervention

Use of iodinated contrast media for diagnostic and interventional procedures is increasing as computed tomography and percutaneous coronary intervention (PCI) technologies provide increasing patient benefit. Although some complications associated with contrast media are mild and transient, contrast-induced nephropathy (CIN) can negatively affect long-term patient morbidity and mortality. The incidence of and outcomes from CIN have been carefully studied in cardiology patients. A number of studies have identified CIN-associated complications in PCI patients, including bleeding, hematoma, stroke, adult respiratory distress syndrome, electrolyte imbalances, and sepsis. In post-PCI patients, rates of myocardial infarction and vessel reocclusion are more common in patients with CIN. Therefore, in-hospital mortality is increased in patients with CIN. In patients requiring dialysis after PCI, several studies have shown the 1-year mortality rate to be >55%. Even moderate renal dysfunction not requiring dialysis is associated with increased mortality in patients with coronary artery disease. Precautionary measures before, during, and after the use of contrast media that reduce the incidence of CIN, such as discontinuation of nephrotoxic medications, adequate hydration, and use of appropriate volumes and types of contrast media, should be considered in all patients with renal insufficiency or with other risk factors for CIN.

The interaction of vascular inflammation and chronic kidney disease for the prediction of long-term death after percutaneous coronary intervention

BACKGROUND

Patients with chronic kidney disease frequently have worse outcomes following percutaneous coronary intervention (PCI) compared to patients with normal renal function. Furthermore, they more commonly have elevated serum markers of inflammation, which may be either directly or indirectly associated with a state of accelerated atherosclerosis. We sought to assess the relationship among glomerular filtration rate (GFR), systemic inflammation, and long-term death after PCI.

METHODS

In patients undergoing PCI, the intensity of vascular inflammation was measured using baseline ultrasensitive C-reactive protein (us-CRP), and GFR was calculated using the Modification of Diet in Renal Disease formula. Their association with long-term death was compared using multivariate Cox regression analysis including an interaction element for us-CRP and GFR, baseline clinical, biochemical, and angiographic variables.

RESULTS

In 4522 patients (mean age 65 +/- 11 years) having undergone PCI, 332 (7.3%) deaths occurred over the median duration of follow-up of 20.1 months (interquartile range 8.5-31.3 months). The mean GFR was 77 +/- 33 mL/min per 1.73 m2 with a median us-CRP of 3.75 mg/L (interquartile range 1.5-10.1 mg/L). Both increasing levels of CRP (log rank P < .001) and decreasing levels of GFR were univariate predictors of long-term death (P < .001). In a multivariate model, both GFR and us-CRP retained independent predictive value for long-term death.

CONCLUSION

Although baseline us-CRP and GFR are both independent predictors of long-term death after PCI, in concert, they impart a markedly exaggerated hazard of mortality.

Outcomes after percutaneous coronary interventions in patients with CKD: improved outcome in the stenting era

BACKGROUND

Percutaneous coronary intervention (PCI) with stenting reduces adverse events in the general population compared with balloon angioplasty. The benefit of stents in high-risk patients normally excluded from clinical trials has not been well studied. Outcomes after PCIs in patients with chronic kidney disease (CKD) before and after widespread use of stents were compared.

METHODS

All patients undergoing PCIs at our center within 2 periods selected for high and low stent use were included. Demographic, kidney and cardiac function, and PCI data were collected. Kaplan-Meier curves were constructed, and Cox proportional hazards analysis was used to assess the effect of high stent use on major adverse cardiac event, a composite of cardiac revascularization, myocardial infarction, or death 3 years after PCI.

RESULTS

A total of 1,879 patients (780 patients, low stent use; 1,099 patients, high stent use; 18% and 94.1% stent use, respectively) with a mean age of 63 years, 73% men, and 26% of patients with a glomerular filtration rate less than 60 mL/min were included. At baseline, there was a greater prevalence of severe CKD, cardiac risk factors, and cardiovascular disease in the high-stent-use cohort. Major adverse cardiac events were reduced in the contemporary cohort (hazard ratio, 0.61; 95% confidence interval, 0.52 to 0.72); this benefit extended across all stages of kidney function.

CONCLUSION

Patients with CKD undergoing PCI in the stenting era show improved outcomes. Additional studies are needed to determine optimal revascularization strategies in patients with CKD.

Chronic kidney disease and cardiovascular disease in a general Japanese population: the Hisayama Study

BACKGROUND

Chronic kidney disease has been shown to be an independent risk factor for cardiovascular disease in high-risk populations. However, this relationship is inconclusive in community-based populations.

METHODS

To clarify this issue, we followed 2634 community-dwelling individuals without cardiovascular disease, aged 40 years or older, for 12 years and examined the relationship between chronic kidney disease and the incidence of cardiovascular disease.

RESULTS

During the follow-up period, 99 subjects (56 men and 43 women) experienced coronary heart disease, 137 subjects (60 men and 77 women) ischemic stroke, and 60 subjects (26 men and 34 women) hemorrhagic stroke. In men, the age-adjusted incidence of coronary heart disease was significantly higher in subjects with chronic kidney disease than in those without it (6.2 vs. 2.9 per 1000 person-years) (P < 0.05), but such a relationship was not observed with ischemic stroke. In contrast, in women, the age-adjusted incidence of ischemic stroke was significantly higher in subjects with chronic kidney disease than in those without it (3.4 vs. 2.5) (P < 0.05), while that of coronary heart disease was not. Chronic kidney disease was not found to be associated with the incidence of hemorrhagic stroke. In multivariate analysis, even after adjustments for traditional and nontraditional cardiovascular disease risk factors, chronic kidney disease was found to be an independent risk factor for the occurrence of coronary heart disease in men [hazard ratio (HR), 2.26; 95% CI, 1.06-4.79], and for the occurrence of ischemic stroke in women (HR, 1.91; 95% CI, 1.15-3.15).

CONCLUSION

Our findings suggest that chronic kidney disease is an independent risk factor for the occurrence of cardiovascular disease in the general Japanese population.

Evaluation and treatment of coronary artery disease in patients with end-stage renal disease

Evaluation and treatment of coronary artery disease in patients with end-stage renal disease. Patients with end-stage renal disease (ESRD) are at increased risk of death from coronary artery disease (CAD). The metabolic milieu that results from renal dysfunction appears to accelerate the atherosclerotic process by decades in patients with ESRD. The extremely high prevalence of atherosclerosis in patients with ESRD mandates risk factor identification and treatment. Traditionally, CAD in this patient population has been treated conservatively. Analysis of large databases has highlighted the scope and complexity of this problem; nonetheless, there is a paucity of randomized, controlled trials of CAD in patients with ESRD. In this paper the following issues related to evaluation and treatment of patients with chronic kidney disease are addressed: (1) optimal CAD risk management; (2) evaluation for CAD in patients with ESRD, including the identification of coronary calcification; (3) treatment of CAD with medical therapy and revascularization; (4) relative merits of percutaneous coronary intervention versus bypass surgery. In general, an aggressive approach to medical management of CAD is warranted, even in the setting of subclinical CAD. A low threshold for diagnostic testing should be employed in patients with ESRD. When significant CAD is identified, ESRD patients appear to benefit more from revascularization compared to conservative medical management. Thus, if clinically reasonable, patients with ESRD and CAD should be managed aggressively to improve survival and reduce the incidence of future cardiac events.

Treatment of acute coronary syndromes in patients who have chronic kidney disease

Patients with CKD and CAD have traditionally been a difficult population to diagnose and treat in the setting of ACS. In addition to having poorer outcomes post-ACS, data are lacking regarding best treatments available. Aggressive interventional and medical treatments in this group with already poor outcomes are not necessarily contraindicated and should always be considered. The appalling outcome for CKD patients post-ACS is improved by many therapies shown to benefit in the non-CKD patients. Data suggest that troponins are useful markers in CKD patients, that major bleeding is not increased with the use of GP IIb-IIIa antagonists, that thrombolytics have been used successfully in CKD patients, and that PCI electively and as a primary treatment for ACS is successful and probably more beneficial to treatment.

Five year clinical effect of coronary stenting and coronary artery bypass grafting in renal insufficient patients with multivessel coronary artery disease: insights from ARTS trial

AIMS

To compare coronary stent implantation and bypass surgery for multivessel coronary disease in patients with renal insufficiency.

METHODS AND RESULTS

In the ARTS trial, 142 moderate renal insufficient patients (Ccr<60 mL/min) with multivessel coronary disease were randomly assigned to stent implantation (n=69) or CABG (n=73). At 5 years, there was no significant difference between the two groups in terms of mortality (14.5% in the stent group vs. 12.3% in the CABG group, P=0.81), or combined endpoint of death, cerebrovascular accident (CVA), or myocardial infarction (MI) (30.4% in the stent group vs. 23.3% in the CABG group, P=0.35). Among patients who survived without CVA or MI, 18.8% in the stent group underwent a second revascularization procedure when compared with 8.2% in the surgery group (P=0.08). The event-free survival at 5 years was 50.7% in the stent group and 68.5% in the surgery group (P=0.04).

CONCLUSION

At 5 years, the differences in mortality and combined incidence of death, CVA, and MI between coronary stenting and surgery did not reach statistically significant level. However, the occurrence of MACCE in the stent group was higher than in the CABG group, mainly driven by the higher incidence of repeat revascularization in the stent group.

Chronic kidney disease as cause of cardiovascular morbidity and mortality

To make an evidence-based evaluation of the relationship between kidney failure and cardiovascular risk, we reviewed the literature obtained from a PubMed search using pre-defined keywords related to both conditions and covering 18 years (1986 until end 2003). Eighty-five publications, covering 552 258 subjects, are summarized. All but three studies support a link between kidney dysfunction and cardiovascular risk. More importantly, the association is observed very early during the evolution of renal failure: an accelerated cardiovascular risk appears at varying glomerular filtration rate (GFR) cut-off values, which were >/=60 ml/min in at least 20 studies. Many studies lacked a clear definition of cardiovascular disease and/or used a single determination of serum creatinine or GFR as an index of kidney function, which is not necessarily corresponding to well-defined chronic kidney disease. In six studies, however, chronic kidney dysfunction and cardiovascular disease were well defined and the results of these confirm the impact of kidney dysfunction. It is concluded that there is an undeniable link between kidney dysfunction and cardiovascular risk and that the presence of even subtle kidney dysfunction should be considered as one of the conditions necessitating intensive prevention of this cardiovascular risk.

Association of chronic kidney disease with clinical outcomes after coronary revascularization: the Arterial Revascularization Therapies Study (ARTS)

BACKGROUND

Chronic kidney disease (CKD) is associated with adverse outcomes after coronary artery bypass graft surgery (CABG) and percutaneous coronary interventions (PCI), but it is unclear which of these revascularization strategies is associated with lower risk for morbidity and mortality in this population. In the Arterial Revascularization Therapies Study (ARTS), we compared long-term clinical outcomes after CABG or PCI with multivessel stenting in patients with CKD.

METHODS

The ARTS randomly assigned 1205 participants with and without CKD to CABG or PCI with multivessel stenting. We defined CKD as creatinine clearance < or =60 mL/min, estimated by the Cockroft-Gault equation. The primary outcome was the composite of death, myocardial infarction (MI), or stroke; and, a secondary outcome was repeat revascularization. Participants were followed for a mean of 3 years after their intervention. We evaluated whether randomization to CABG or PCI was associated with different outcomes among participants with CKD.

RESULTS

Two hundred ninety participants (25%) had CKD at entry into ARTS. One hundred fifty-one received PCI, and 139 received CABG. No difference was observed in the primary endpoint with CABG or PCI among CKD participants (adjusted Hazard Ratio [HR] CABG vs PCI = 0.93; 95% CI 0.54-1.60; P = .97). However, CABG was associated with a reduced risk for repeat revascularization (HR = 0.28; 95% CI 0.14-0.54; P < .01). Compared with participants with normal renal function, CKD was associated with a nearly 2-fold risk for the primary outcome (unadjusted HR = 1.9; 95% CI 1.4-2.7; P < .01). After multivariate adjustment, this association remained significant (HR 1.6; 95% CI 1.1-2.4).

CONCLUSIONS

In patients with multivessel CAD and CKD, treatment with CABG or PCI with multivessel stenting led to similar outcomes of death, MI, or stroke, but CABG was associated with decreased repeat revascularizations. When compared with ARTS participants with normal renal function, those with CKD had substantially elevated risk of adverse clinical outcomes after coronary revascularization.

Survival After Coronary Revascularization Among Patients With Kidney Disease

BACKGROUND

The optimal approach to revascularization in patients with kidney disease has not been determined. We studied survival by treatment group (CABG, percutaneous coronary intervention [PCI], or no revascularization) for patients with 3 categories of kidney function: dialysis-dependent kidney disease, non-dialysis-dependent kidney disease, and a reference group (serum creatinine <2.3 mg/dL).

METHODS AND RESULTS

Data were derived from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH), which captures information on all patients undergoing cardiac catheterization in Alberta, Canada. Characteristics and patient survival in 662 dialysis patients (1.6%) and 750 non-dialysis-dependent kidney disease patients (1.8%) were compared with the remainder of the 40,374 patients (96.6%). For the reference group, the adjusted 8-year survival rates for CABG, PCI, and no revascularization (NR) were 85.5%, 80.4%, and 72.3%, respectively (P<0.001 for CABG versus NR; P<0.001 for PCI versus NR). Adjusted survival rates were 45.9% for CABG, 32.7% for PCI, and 29.7% for NR in the nondialysis kidney disease group (P<0.001 for CABG versus NR; P=0.48 for PCI versus NR) and 44.8% for CABG, 41.2% for PCI, and 30.4% for NR in the dialysis group (P=0.003 for CABG versus NR; P=0.03 for PCI versus NR).

CONCLUSIONS

Compared with no revascularization, CABG was associated with better survival in all categories of kidney function. PCI was also associated with a lower risk of death than no revascularization in reference patients and dialysis-dependent kidney disease patients but not in patients with non-dialysis-dependent kidney disease. The presence of kidney disease or dependence on dialysis should not be a deterrent to revascularization, particularly with CABG.

Cardiovascular disease and chronic kidney disease: insights and an update

Despite the high prevalence and significant morbidity and mortality rates of chronic kidney disease (CKD) related to cardiovascular disease, it remains vastly understudied. Most of the current practice recommendations come from small under-powered prospective studies, retrospective reviews, and assuming patients with CKD will similarly benefit from medications and treatments as patients with normal renal function. In addition, because of the previous lack of a consistent definition of CKD and how to measure renal function, definitions of the degree of renal dysfunction have varied widely and compounded the confusion of these data. Remarkably, despite patients with CKD representing the group at highest risk from cardiovascular complications, even greater than patients with diabetes mellitus, there has been a systematic exclusion of patients with CKD from therapeutic trials. This review outlines our current understanding of CKD as a cardiovascular risk factor, treatment options, and the future directions that are needed to treat cardiovascular disease in patients with CKD.

The evaluation of underlying cardiovascular disease among patients with end-stage renal disease

Although coronary artery disease (CAD) is highly prevalent among patients with chronic kidney disease (CKD), interventions proven to reduce cardiovascular disease (CVD) mortality are underutilized in this population of patients. Given the burden of CVD in this population, knowledge of specific diagnostic tests for detection and evaluation of CAD in patients with end-stage renal disease (ESRD) and their correlation with outcomes is imperative for the practicing nephrologist. Studies that examine the use of exercise electrocardiography testing, pharmacologic stress imaging, single-photon emission computed tomographic myocardial perfusion imaging, electron beam computed tomography, and dobutamine stress echocardiography among patients with ESRD are detailed with recommendations for the noninvasive evaluation of CAD in this population.

Coronary revascularization in patients with coronary artery disease and chronic kidney disease

There is a remarkable lack of randomized trial data on optimal management of coronary artery disease (CAD) in patients with chronic kidney disease (CKD). In fact, patients with CKD are often excluded from randomized trials that compare different treatment strategies for CAD. Because the most common cause of death in CKD patients is cardiovascular disease, it is crucial that studies are designed to determine the best therapy for CAD in this high-risk group. This article discusses the available data on coronary revascularization outcomes in CKD patients.