CHAPTER 14: Cardiac Evaluation in the Pretransplant Patient

INTRODUCTION

The failing kidney affects multiple organ systems in the body as it becomes ineffectual in clearing toxins, producing hormones, and metabolizing substrates. Frequently, the cardiovascular system is affected in patients with chronic kidney disease (CKD), causing a burden of morbidity and mortality. More than two decades ago, Foley et al. had studied a USRDS data set and found that cardiovascular disease mortality is 10–20 times higher in ESRD patients compared with the general population after stratification for age, race, and sex.¹ Cardiovascular events form a common cause of death in this patient group. In evaluating the cardiovascular system in patients yet to undergo a renal transplant, it has been shown that²:

• CKD increases cardiovascular risk and portends a worse outcome if an event occurs.

• Cardiovascular disease (CVD) accounts for approximately 50% of end-stage renal disease (ESRD) deaths.

• The prevalence of angiographically significant coronary artery disease (CAD) ranges from 25% in young, nondiabetic hemodialysis patients to 85% in older ESRD patients with long-standing diabetes.

• When compared to patients without CKD who undergo evaluation for CAD, those with ESRD have substantially more numerous and severe coronary artery lesions, as well as more severe left ventricular dysfunction.

ESTIMATED CARDIOVASCULAR DISEASE PREVALENCE AND MORTALITY

From the United States Renal Data System (USRDS) 2017 Annual Data Report,³ the prevalence of CAD was 2.4 times higher in patients with CKD versus without CKD. Furthermore, acute myocardial infarction (AMI) and heart failure (HF) had a fourfold higher prevalence. Two-year survival rates of patients with any CKD and a prevalent CVD were lower when compared to patients without CKD, with worsening survival rates among those with CKD stages 4 to 5.

There is an increased prevalence of CAD and higher annual cardiovascular mortality in patients with ESRD on dialysis. There is evidence to support that the risk is reduced posttransplant, where the prevalence of CAD becomes comparable to the general population. Annual cardiovascular mortality is lower post-transplant compared to patients with ESRD or mild to moderate CKD, but remains twofold greater than that of the general population.⁴

CKD has been strongly associated with myocardial infarction (MI). The combination of disease of both these vital organs becomes particularly problematic in this patient group, enhancing their mortality risk in the event of an MI. Evidence suggests that a decline in renal function reduces survival rates in the period following an MI compared to a population with normal renal function.⁴

The evidence concludes that not only is CVD more prevalent among patients with CKD, it is also more likely to cause death in the interval following a cardiovascular event.

CARDIOVASCULAR RISK FACTOR MODIFICATION IN PATIENTS WITH CKD

In 1948, the Framingham Heart Study, under the direction of what is now the National Heart, Lung and Blood Institute (NHLBI), ...