Perspective:

The following are points to remember about this expert consensus document from the European Society of Cardiology:

1. Hypertension is one of the most frequent chronic diseases worldwide. It is estimated that over the next two decades, up to 50% of the adult population will be diagnosed with hypertension.

2. Resistant hypertension, defined as uncontrolled blood pressure that persists despite the use of three or more antihypertensives of different classes, including a diuretic, at maximal or the highest tolerated dose, is present in 5-10% of patients with hypertension.

3. Renal denervation targeting both afferent and efferent nerves has been demonstrated to reduce sympathetic nerve activity, norepinephrine spillover, and blood pressure in patients with resistant hypertension.

4. There are currently five devices that have a CE mark (Conformité Europeénne). Four of the catheter-based systems use radiofrequency energy (Medtronic’s Symplicity system, St. Jude’s EnligHTN system, Vessix’s V2 system, Covidien’s One Shot system), and one uses ultrasound energy (Recor’s Paradise system).

5. The renal artery needs to be at least 4 mm in diameter and at least 20 mm in length for successful denervation, and should be free of significant stenosis or calcification.

6. Transient local de-endothelialization, acute cellular swelling, connective tissue coagulation, and thrombus formation have been demonstrated to occur after renal denervation. Use of aspirin for 4 weeks is empirically recommended based on these findings.

7. Improvement in blood pressure rarely occurs immediately, and it often takes several weeks to months before a notable blood pressure reduction is evident. Further, a reduction in pill burden has not been demonstrated in the currently completed randomized trials, although consistent reduction in blood pressure has been noted in both randomized and observational studies.

8. Renal denervation results in a significant drop in resting, maximum exercise, and recovery blood pressure, whereas heart rate response during exercise and oxygen uptake is well preserved.

9. Renal denervation is currently being evaluated for heart failure and metabolic syndrome, with small studies demonstrating promising results. Further, the therapy has also been demonstrated to reduce the occurrence of atrial fibrillation and ventricular arrhythmias.

10. The ongoing SYMPLICITY-3 trial is expected to close enrollment soon, and its results will establish the clinical utility of this therapy.