Traditional cardiovascular risk factors, particularly hypertension and diabetes, are common in the disease processes of both renal and cardiac pathology. Unfortunately the coexistence of renal impairment is not an innocent bystander in cardiovascular disease; it disorder not only increases the prevalence and severity of cardiovascular disease, but also negatively affects prognostic outcomes and the safety and efficacy of cardiac interventions. This article discusses the role and impact of kidney disease in the cardiac patient in 3 key common cardiovascular processes: coronary artery disease, arrhythmia, and heart failure.

Keywords

Cardiac

Cardiovascular disease

Chronic kidney disease

Chronic renal failure

Atrial fibrillation

Coronary artery disease

Chronic heart failure

Key points

Introduction

Cardiovascular disease (CVD) and chronic kidney disease (CKD) are both encompassing terms that incorporate a spectrum of pathology that in the case of CVD includes arterial atherosclerosis, heart failure, diseases of the myocardium and pericardium, valvular disease, and cardiac arrhythmias. CKD in turn incorporates vascular, glomerular, tubulointerstitial, and obstructive nephropathies that result in a persistent (minimum of 3 months) depression of glomerular filtration rate (GFR) lower than 90 or, more typically, 60 mL/min/1.73 m2 (mild and moderate CKD, respectively) and/or the presence of albuminuria. The severity of CKD is classified into 5 categories, as defined by the National Kidney Foundation and the Kidney Disease Outcome Quality Initiative (Table 1).1 Despite the diversity of underlying abnormality in each pathologic condition, there appear to be several etiologic factors shared between CVD and CKD. The noninheritable, noninfectious CVDs typically incorporate “traditional” cardiovascular risk factors that include age, gender, hypertension, diabetes, dyslipidemia, smoking, and other lifestyle factors including obesity. Given that the most common forms of CKD share a significant number of these risk factors, particularly hypertension and diabetes (Fig. 1),2 it is unsurprising that a substantial proportion of cardiac patients also have significant renal impairment: approximately one-third of patients presenting for coronary angiography will have CKD3–5; in patients with heart failure the prevalence of CKD is estimated at between 32% and 53% (with the highest prevalence in those with acute decompensation)6 and more than half of patients with atrial fibrillation (AF) have CKD,7 increasing to nearly three-fourths of elderly AF patients (>80 years) considered for anticoagulant therapy.8

By contrast, CVDs such as coronary artery disease and heart failure are highly prevalent in the CKD population, and increasingly so with deteriorating renal function: in severe CKD (stage IV), the prevalence of coronary artery disease (CAD) and heart failure reaches 19.0% and 12.5%, respectively.1 Within this same patient cohort, the prevalence of hypertension and diabetes in individuals with CKD approaches 50% and 20%, respectively. Significantly, these 2 comorbidities represent an increasing worldwide burden: in 2013, 1 billion people were treated for hypertension and 240 million patients for diabetes, with the totals projected to increase to an estimated 1.56 billion with hypertension by 2025 and 380 million with diabetes over the next decade.2 In these groups, the prevalence of CKD is 37% and 26%, respectively, as reported by the US National Health and Nutrition Examination Surveys.9 The prevalence of CKD is therefore anticipated to increase significantly worldwide over the coming decades, and although there have been significant improvements in the rates of cardiovascular mortality (particularly with deaths related to CAD, which have fallen by approximately 50% over the last 3 decades10), globally the pressure exerted by increasing prevalence of these comorbidities is contrary to the continuation of this positive trend.

CVD and CKD are intricately linked, and their prognoses interwoven. This review discusses how CKD affects common CVD prognosis, and the efficacy of and the adverse events arising from clinical cardiovascular interventions.

Coronary artery disease

Atherosclerotic CAD is a prototypical example of the interaction between CKD and CVD. Mild renal dysfunction is increasingly recognized as a nontraditional cardiovascular risk factor for CAD: modest elevations of urinary albumin excretion below the current microalbuminemia diagnostic threshold are associated with elevated cardiovascular risk,11 which increases proportionately with progressive renal deterioration.12 Moreover, CKD, once established, doubles the rates of both CVD progression13 and in-hospital death following primary percutaneous intervention (PCI) in comparison with those without CKD.14 The accelerated progression of CVD in CKD is likely to be multifactorial, incorporating several nontraditional risk factors that include hyperphosphatemia (and vascular calcification),15 oxidative stress and systemic inflammation,16 hyperhomocysteinemia, hypervolemia, mineral/electrolyte imbalance, anemia,17 thrombogenesis, and malnutrition. Consequently, in the CKD patient cohort, CVD mortality is not only 10 to 30 times higher than in the general population,1 but CVD is a also more likely adverse outcome than progressing to end-stage renal disease (ESRD) in these patients.18,19 Clinical management strategies therefore must center on the management of the underlying kidney disease and the common causes of hypertension and diabetes; there is emerging evidence that multidisciplinary approaches by nephrologists to control the progression of renal disease pays dividends in diminishing the rates of cardiovascular mortality in these patients.20