Renal Denervation for Chronic Heart Failure: Background and Pathophysiological Rationale

The activation of the sympathetic nervous system is associated with cardiovascular hospitalizations and death in heart failure. Renal denervation has been shown to effectively reduce sympathetic overdrive in certain patients with uncontrolled hypertension. Pilot trials investigating renal denervation as a potential treatment approach for heart failure were initiated. Heart failure comorbidities like obstructive sleep apnea, metabolic syndrome and arrhythmias could also be targets for renal denervation, because these occurrences are also mediated by the activation of the sympathetic nervous system. Therefore, renal denervation in heart failure is worthy of further investigation, although its effectiveness still has to be proven. Herein, we describe the pathophysiological rationale and the effect of renal denervation on surrogates of the heart failure syndrome.

Blood pressure control and predictors of uncontrolled hypertension

Improving blood pressure control requires the identification of covariates associated with uncontrolled hypertension. To evaluate blood pressure control and predictors for uncontrolled hypertension. A Cross-Sectional Study. Cardiology Out-patient Department, Salmaniya Medical Complex. We documented personal factors, comorbidities, blood pressure measurements and the use of anti-hypertensive medications in 371 hypertensive patients from 1 January 2012 to 30 April 2012. Ordinal logistic regression was used to identify factors associated with poor blood pressure control. The mean age of the patients was 54.6 +/- 11.8 years. Two hundred forty-six [66.3%] patients had a mean blood pressure of <140/90; the rest had a mean blood pressure of >140/90. Age group 45-65 years, multidrug regimen, and poorly controlled diabetes were independent predictors of poor blood pressure control. Three hundred thirty-eight [91.1%] patients were on polytherapy receiving an average of three medications. The poorest blood pressure control was among diabetics, 207 [55.8%] and renal impairment patients 67 [18.1%]. The rate of BP control could be improved in the Cardiology Secondary Care Ambulatory Department. Most of the patients were on triple combination therapy. Diabetes and renal impairment are the main risk factors for poor blood pressure control

Effect of renal sympathetic denervation used in the treatment of resistant arterial hypertension on left ventricular hypertrophy and diastolic function

Background: Hypertension [HTN] results in structural and functional cardiac changes which increase cardiovascular morbidity and mortality. The effect of renal denervation [RD] on left ventricular hypertrophy [LVH] and left ventricular [LV] diastolic function is still unclear

Objective: This study investigated the effect of catheter-based renal sympathetic denervation on LVH and diastolic function in patients with resistant hypertension

Methods: We evaluated systolic and diastolic blood pressure [SBP and DBP, LV size, mass and diastolic function before and 6 months after RD in 68 patients with resistant hypertension by transthoracic echocardiography and Doppler

Results: SBP and DBP reduced 6 months after RD [-22 +/- 3 mmHg and -10 +/- 12mmHg; P<0.0001 respectively] LV mass index decreased similarly independent on BP response [-19.37 +/- 2.6 gm/m[2]: P<0.0001]. Diastolic parameters E/A ratio, E-wave deceleration time and intra-ventricular relaxation time improved similarly in all patients after 6 months [0.89 +/- 0.04; P=0.001, -24.85 +/- 8.93 ms; P=0.007 and -6.97 +/- 2.57 ms; P=0.012 respectively]

Conclusion: In patients with resistant hypertension and beside blood pressure lowering effect, renal denervation improves left ventricular hypertrophy and diastolic function. The relation of BP reduction effect and the improvement of cardiac hypertrophy and systolic function suggests a direct effect of sympathetic activity on LV remodeling and function which needs to be confirmed in larger prospective cohorts