End of Year Hypertension News for 2013: In Like a Lamb-Out Like a Lion

As the calendar year was closing out on good old 2013, 3 publications affecting the management of hypertension appeared back to back to back. The CORAL Study (Cardiovascular Outcomes in Renal Atherosclerotic Lesions), addressing the purported benefits (or lack thereof) of dilatation and stenting moderate to severe renal artery stenosis, was in The New England Journal of Medicine in November.¹ Simplicity HTN-1, studying the impact of renal denervation therapy on resistant hypertension, made the pages of Lancet.² And, the long-awaited, already pejoratively nicknamed (JNC late or JNC wait) JNC “8” (JNC 7 dated way back to 2003) could be read in December’s JAMA.³ What do these 3 reports tell us about the management of hypertension in 2014 and beyond?

First there was CORAL.¹ There were already data demonstrating that renal artery dilatation and stenting in the setting of renal artery stenosis (an important cause of hypertension associated with cardiovascular and peripheral vascular disease and their lethal complications) was not beneficial.⁴ Medical therapy was just as good. The ASTRAL study,⁴ however, was criticized because some of the enrolled cohort did not have substantial, severe enough renal artery disease for critics. Could it be that individuals with more severe renal vascular disease would benefit from a dilated artery? Well, after further review, the answer is still no. A total of 947 persons with “substantial” atherosclerotic (not fibromuscular) renal vascular disease (a mean arterial narrowing of 73%) were randomized in the trial. They were divided thusly: 467 received stenting plus medical therapy (antihypertensives) and 480 medications only. The end points were “hard”: major cardiovascular or renal events such as death and renal failure. Persons in the study had systolic blood pressures of 155 mm Hg or greater or CKD-3 (a GFR less than 60 cc/min) accompanying by significant renal artery narrowing. When the trial ended, medical therapy was still the choice for arteriosclerotic renal vascular disease. Dilatation and stenting do not add benefits for those trying to avoid vascular and renal end points.

Resistant hypertension-that is, failure to reach target (more on “targets” when we get to JNC 8), on a complementary 3-drug antihypertensive regimen including a diuretic-is increasing in prevalence and can be fatal. What should we do after 3 drugs fail?

One choice is renal denervation therapy. Sympathetic nerves to the kidneys contribute to hypertension-especially to resistant hypertension. Technology can “denervate” their contributions to hypertension by radiofrequency ablation. Important questions remain, however. How effective and durable are the blood pressure–lowering effects of renal denervation therapy? Simplicity HTN-1 set out to answer that question.² The study was successful in accomplishing that end. Renal denervation therapy effected a 20 mm Hg systolic pressure drop in 77% of those treated that was durable, sustained at 36-month follow-up.

My only concern is that every time the procedure is described, ink is given to pain incurred during denervation. Nonetheless, especially in Europe, renal denervation therapy has evolved into a scientifically established treatment modality for resistant hypertension.

The final question for study in 2013-at least for this author-was JNC 8 worth the wait? That is the subject for my next installment.   

References
1. Cooper CJ, Murphy TP, Cutlip DE, et al. Stenting and medical treatment for atherosclerotic renal artery stenosis. N Engl J Med. 2013 Nov 18; [Epub ahead of print].           
2. Krum H, Schlaich MP, Bohm M, et al. Percutaneous renal denervation in patients with medication resistant blood pressure: final 3 year report of the SIMPLICITY HTN-1 Study. Lancet. 2013 Nov 6; [Epub ahead of print].
3. James PA, Oparil S, Carter B, et al. 2014 Evidence-Based Guideline for the management of High Blood Pressure in Adults Report from the Panel Members appointed to the Eighth Joint National Committee (JNC 8). JAMA. 2013; doi:10.1001/jama.2013.284427.
4. The ASTRAL Investigators. Revascularization versus medical treatment for renal artery stenosis. N Engl J Med. 2009;361:1953-1962.