UKidney Nephrology News and Insights

Poster: Racial/Ethnic Disparities in Atrial Fibrillation Treatment and Outcomes in US Dialysis Patients

Presenter: Adan Z. Becerra PhD, Social & Scientific Systems

Authors: Paul L. Kimmel, MD, FASN, National Institute of Diabetes and Digestive Kidney Diseases (NIDDK), Salina Paulette Waddy, MD, Atlanta Veterans Administration, Allen J. Solomon, MD, The George Washington University, Adan Z. Becerra PhD, Social & Scientific Systems, Julia B. Ward, PhD, MPH, Social & Scientific Systems, Inc., Kevin Chan, MD, MS, MGH, Chyng-Wen Fwu PhD, Social & Scientific Systems, Inc., Jenna M. Norton MPH, NIH/NIDDK, Paul Eggers PhD, Kevin C. Abbott, MD, MPH, The National Institutes of Health, NIDDK,

Increased racial/ethnic disparities in stroke rates among end-stage renal disease (ESRD) dialysis patients with atrial fibrillation (AF) are partially explained by lower use of oral anticoagulants among Blacks, Hispanics, and Asians. The reasons for these racial disparities in practice are unknown, although the results support an identified need to develop strategies that will maximize stroke prevention in minority populations and resolve system barriers between patient/physician that may block optimal treatment.

A 53 M presents for follow-up of his hypertension. He has a history which includes:

Upon reflection, what percentage of the patients in your practice are on an optimal medication regimen in terms of dosing and medications selected?

Hypertension is one of the most important risk factors for adverse health outcomes that we treat either in specialty or primary care. However, controversy has always existed in terms of the target blood pressure that clinicians should aim for when managing patients with different comorbidities. The SPRINT study published in 2015 continues to offer insight and some controversy guiding therapy in patients with hypertension particularly those at high cardiovascular risk.

Drs. Anish Kirpalani and Darren Yuen, both of St. Michael's Hospital in Toronto, appear to be on the verge of a major practice-changing advance in the assessment of chronic kidney disease. Their study, appearing in cJASN, describes the new methodology which assesses kidney fibrosis in a novel way using MRI. We caught up with the authors of this exciting study and they shared some further perspective on their exciting findings.

Topline results of the Reprise Study in ADPKD have been announced and the good news continues for ADPKD. According to top-line results released by Otsuka, the maker of Tolvaptan:

A long awaited analysis of the renal outcomes from the EMPA-REG study was published in the New England Journal of Medicine on June 14th [2].  As originally reported on UKidney, compared to patients taking placebo, the use of empagliflozin was associated with significant improvements in important renal end-points, namely doubling of serum creatinine and end-stage renal disease (ESRD). While these results are indeed very promising, some perspective is warranted when considering the potential nephroprotective properties of this drug, and of the SGLT2 inhibitor class in general.

The SPRINT Study was received with great fanfare when it was published on November 26th in the New England Journal of Medicine. The primary results, summarized in the publication’s abstract are these:

"Among patients at high risk for cardiovascular events but without diabetes, targeting a systolic blood pressure of less than 120 mm Hg, as compared with less than 140 mm Hg, resulted in lower rates of fatal and nonfatal major cardiovascular events and death from any cause, although significantly higher rates of some adverse events were observed in the intensive-treatment group."

The essential word in that abstract’s conclusion - and which prevents the application of these results - is ‘targeting’. The conclusion accepted by many is that aggressive blood pressure reduction, that is the achieved blood pressure, drove the observed results. However, it may well be that the act of targeting a low blood pressure, and using cardioprotective drugs to do so, explained the results rather than the reduction of blood pressure itself. And unravelling this nuance is the key to understanding whether SPRINT’s main message is applicable to the general population. I would argue that in its current form SPRINT suffers from a major methodological short-coming that leaves us in a quagmire.

As we continue to process data from the EMPA-REG renal outcomes presentation - which most importantly showed a 46% reduction in the composite of creatinine doubling, end-stage renal disease or renal death - speculation is well underway to explain the mechanism for renal protection. And the emerging story appears to be quite fascinating indeed.