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Personalized decision support and the move from NNT to iNNT

The SPRINT trial made waves in the field of hypertension, showing evidence for reduced hard clinical endpoints (a combined outcome of myocardial infarction, acute coronary syndrome not resulting in myocardial infarction, stroke, acute decompensated heart failure, or death from cardiovascular causes) in those patients with a BP target of 120 mm Hg systolic. At the same time, it was clearly shown than more intensive blood pressure control drove increased risk of adverse events, including hypotension, syncope, electrolyte abnormalities, and acute kidney injury or failure. The challenge with randomized clinical trials is that the results, while considered valid for the total population studied, may not apply to individual patients who simply meet the enrolment criteria for the study. Some of those patients would derive more benefit and less harm, while others will see more harm and less benefits.  As the world moves towards personalized medicine, it would be ideal to be able to individualize how we apply the results of a clinical trial. The CREBP Journal Club reviewed SPRINT and made the comment (which they shared in their PubMed Commons post): Whether the interventions are beneficial for an individual patient appears to be dependent on the individual clinical circumstances and the preferences of the patient. We would strongly recommend the development of methods for improving shared decision making with patients on this topic before recommending this intervention be part of routine practice. Well, enter the SPRINT data analysis challenge, and researchers like  Noa Dagan, MD, MPH, the head of data at Clalit Research Institute, Rahul Aggarwal, Boston University School of Medicine, and Joseph Rigdon, PhD from Stanford University. Researchers like these re-analyzed...

Will SPRINT Change Our Systolic BP Target in Hypertensive Patients from 140 to 120 mm Hg?

At last week’s Medicine rounds at the Royal Columbia Hospital, I presented the results from the recently published SPRINT trial.  SPRINT Research Group, Wright JT Jr, Williamson JD, Whelton PK, Snyder JK, Sink KM, Rocco MV, Reboussin DM, Rahman M, Oparil S, Lewis CE, Kimmel PL, Johnson KC, Goff DC Jr, Fine LJ, Cutler JA, Cushman WC, Cheung AK, Ambrosius WT. A Randomized Trial of Intensive versus Standard Blood-Pressure Control. N Engl J Med. 2015 Nov 26;373(22):2103-16. PMID: 26551272.   The paper and related editorials/publications can be found in this shared collection: In short, my thoughts are that this is a very well done study with no concerning methodologic issues that affect the validity of the results. With a clinically and statistically significant reduction cardiovascular outcomes and mortality, the benefits of a systolic BP target of <120 mm Hg appear to be quite meaningful in the population studied, despite the high NNTs. It should be clearly noted that this study excludes those with prior stroke, diabetes, nursing home residents, among others. That being said, it appears to be broadly applicable (with ~17 million Americans fitting the enrollment criteria), including the elderly and many with chronic kidney disease. As a nephrologist, I was really encouraged to see that almost 30% of patients enrolled had CKD (with GFR 20-60 ml/min, with the exclusion of PKD, GN requiring immunosuppression, and proteinuria > 1 gm/day).  My clinical practice is certainly made up of plenty of patients who would satisfy the inclusion and exclusion criteria of the study. Caution should be taken before applying the findings of this study to all patients who meet the enrollment...

Temporary Visitor Visas for Donating a Kidney

As a resident in the newly created Vancouver-Granville riding and a nephrologist (internal medicine doctor specializing in kidney medicine), I’m asking the following of my political candidates: Immigration Canada should offer expedited approval for a Visitors Visa to those individuals coming to Canada for living kidney donation to a Canadian or permanent resident (with the requirement for documentation from a Canadian nephrologist). I frequently look after patients who need a kidney transplant. They often have family or friends in other countries who would like to donate a kidney, but are unable to get an expedited visitor’s visa from Immigration Canada in order to facilitate a transplant. When patients don’t get kidney transplants, they have worse health outcomes (including much higher risk of dying) and it costs our healthcare system strikingly more to look after their care. In fact, the evidence to date demonstrates a significant advantage for allograft and patient survival associated with preemptive transplantation. In addition, preemptive transplantation is associated with better quality of life for these patients and is less costly than dialysis.  Meier-Kriesche HU1, Schold JD. The impact of pretransplant dialysis on outcomes in renal transplantation. Semin Dial. 2005 Nov-Dec;18(6):499-504. PMID: 16398713.   We also know that time is of the essence.  Getting a transplant prior to starting dialysis (known as pre-emptive transplantation) results in much better patient outcomes than waiting to get a transplant after one starts dialysis.  Davis CL1. Preemptive transplantation and the transplant first initiative. Curr Opin Nephrol Hypertens. 2010 Nov;19(6):592-7. PMID: 20827196.   This means we need to move fast when we recognize a patient is about to start dialysis.  And getting a temporary...