Faculty Bibliography

Chronic kidney disease (CKD) is a major risk factor for valvular heart disease (VHD). Mitral annular and aortic valve calcifications are highly prevalent in CKD patients and commonly lead to valvular stenosis and regurgitation, as well as complications including conduction system abnormalities and endocarditis. VHD, especially mitral regurgitation and aortic stenosis, is associated with significantly reduced survival among CKD patients. Knowledge related to VHD in the general population is not always applicable to CKD patients because the pathophysiology may be different, and CKD patients have a high prevalence of comorbid conditions and elevated risk for periprocedural complications and mortality. This Kidney Disease: Improving Global Outcomes (KDIGO) review of CKD and VHD seeks to improve understanding of the epidemiology, pathophysiology, diagnosis, and treatment of VHD in CKD by summarizing knowledge gaps, areas of controversy, and priorities for research.

BACKGROUND:Central arteriovenous fistula (cAVF) has been investigated as a therapeutic measure for treatment resistant hypertension in patients without advanced chronic kidney disease (CKD). There is considerable experience with the use of arteriovenous fistula (AVF) for hemodialysis in patients with end stage renal disease (ESRD). However, there is sparse data on the blood pressure (BP) effects of an AVF among patients with ESRD. We hypothesized that AVF creation would significantly reduce BP compared to patients who did not have an AVF among patients with ESRD before starting hemodialysis. METHODS:Blood pressures were compared during the 12 months before hemodialysis initiation in 399 patients with an AVF or AV graft created and 4696 patients without either. RESULTS:After propensity score matching 1:2 ratio (AVF to no AVF), repeated measures analysis of variance revealed significant reductions of -1.7 mmHg systolic and -3.9 mmHg diastolic BP 12 months in patients after AVF creation; p=0.025 and p < 0.001, respectively, as compared to those with no AVF. CONCLUSIONS:These findings suggest that AVF creation results in modest BP reduction in patients with pre-dialysis ESRD who require AVF for eventual hemodialysis therapy. Preferential DBP reduction suggest greater work is needed to characterize the ideal patient subset in which to use cAVF for treatment resistant hypertension in those without advanced CKD.

Purpose of Review: Stent design continues to evolve with newer generation of stents aimed at improving clinical outcomes. This review compares different generations of stents with a focus on biodegradable polymers and stents and their potential benefits. Recent Findings: Drug-eluting stents (DES) reduce stent thrombosis when compared with bare-metal stents (BMS). However, they are associated with impaired vascular healing/endothelialization and excess very long-term events (beyond 1 year). Much of these events (beyond 1 year) have been attributed to continued inflammation due to the polymer. Biodegradable-polymer drug-eluting stents (BP DES) were designed to overcome this polymer related limitation of first-generation DP DES by combining the benefits of reduced in-stent restenosis seen with DES and the benefits of reduced very-late stent thrombosis and myocardial infarction due to absence of polymer with bare-metal stents (BMS). Earlier generation of BP DES showed superiority over first-generation DP DES but at best non-inferior to second-generation DP DES for clinical outcomes; however, the newer-generation BP DES with ultrathin struts show promise in further reducing clinical outcomes when compared with second-generation DP DES. Whether this is due to the biodegradable polymer or the ultrathin struts continues to be debated. Summary: Biodegradable polymer stents in conjunction with ultrathin struts have shown promise as the next generation of DES; however, additional studies and long-term follow-up are needed to confirm these effects.

Beta-blockers are commonly used medications, and they have been traditionally considered 'cardioprotective'. Their clinical use appears to be more widespread than the available evidence base supporting their role in cardioprotection. Beta blockers counteract neurohumoral activation in heart failure with reduced ejection fraction and offer both symptomatic improvement and reduction in adverse events. On the other hand, use of beta-blockers in uncomplicated hypertension results in suboptimal outcomes compared to the established first-line antihypertensive agents. Providers at all levels should be familiar with common misconceptions regarding beta-blocker use in routine clinical practice.