Renal Denervation

Question 1

Define drug refractory hypertenison

Answer 1

Persistent drug resistant hypertension after evaluation by a hypertension specialist or hypertension centre

Question 2

What is apparent treatment resistant hypertension?

Answer 2

These are epidemiological studies and refers to patients with an office bp above 140/90 while taking three or more antihypertensives.

No factoring of adherence, dose, and accuracy of bp check

Question 3

Define severe drug resistant ht?

Answer 3

Drug resistant ht with bp of 160 or above

Question 4

What are some of the functions of the efferent sympathetic fibres to the kidney?

Answer 4

Salt and volume retention
Increase renin activity
Reduction of renal blood flow and gfr

Question 5

Describe the renal denervation procedure?

Answer 5

Usually a femoral approach
Usually 1 hr
Kidney artery of least 2cm before bifurcation is required
4mm diameter on both sides that supply most of the kidney
If an accessory artery perfuses substantial kidney these patients were excluded from the studies
Radiofrequency ablation energy applied for 2 mins 50-70 degrees and done circumfentially

Question 6

What is the average drop in bp at 6 months post renal denervation?

Answer 6

10 mmhg

Question 7

What is the most current evidence relating to sympathetic denervation?

Answer 7

Simplicity 3 trial 535 patients with severe resistant ht 2;1 underwent denervation and sham.

At 6 months mean bp drop treatment group 14 vs 12. 24 hr monitoring 6.8 vs 4.8 not significant

Question 8

Define drug resistant hypertension

Answer 8

Repeated bp above >140/>90 in the office/clinic while taking 3 or more antihtives in OPTIMAL DOSES with at least one diuretic.

Or

Any office/clinic bp irrespective if actual values in a patient taking four or more antihypertensives