Effects of catheter-based renal denervation on renin-aldosterone system, catecholamines, and electrolytes: A systematic review and meta-analysis

Ten-year follow-up of very-high risk hypertensive patients undergoing renal sympathetic denervation

OBJECTIVES

Renal denervation (RDN) has been proven to be effective in lowering blood pressure (BP) in patients, but previous studies have had short follow-ups and have not examined the effects of RDN on major cardiovascular outcomes. This study aimed to demonstrate the effectiveness and safety of RDN in the long-term treatment of hypertension and to determine if it has an effect on cardiovascular outcomes.

METHODS

All patients with resistant hypertension who underwent RDN between 2011 and 2015 at Tianjin First Central Hospital were included in the study. Patients were followed up at 1,5 and 10 years and the longest follow-up was 12 years. Data were collected on office BP, home BP, ambulatory BP monitoring (ABPM), renal function, antihypertensive drug regimen, major adverse events (including acute myocardial infarction, stroke, cardiovascular death and all cause death) and safety events.

RESULTS

A total of 60 participants with mean age 50.37 ± 15.19 years (43.33% female individuals) completed long-term follow-up investigations with a mean of 10.02 ± 1.72 years post-RDN. Baseline office SBP and DBP were 179.08 ± 22.05 and 101.17 ± 16.57 mmHg under a mean number of 4.22 ± 1.09 defined daily doses (DDD), with a reduction of -35.93/-14.76 mmHg as compared with baseline estimates ( P  < 0.0001). Compared with baseline, ambulatory SBP and DBP after 10-years follow-up were reduced by 14.31 ± 10.18 ( P  < 0.001) and 9 ± 4.35 ( P  < 0.001) mmHg, respectively. In comparison to baseline, participants were taking fewer antihypertensive medications ( P  < 0.001), and their mean heart rate had decreased ( P  < 0.001). Changes in renal function, as assessed by estimated glomerular filtration rate (eGFR) and creatinine, were within the expected rate of age-related decline. No major adverse events related to the RDN procedure were observed in long-term consequences. All-cause mortality and cardiovascular mortality rates were 10 and 8.34%, respectively, for the 10-year period.

CONCLUSION

The BP-lowering effect of RDN was safely sustained for at least 10 years post-procedure. More importantly, to the best of my knowledge, this is the first study to explore cardiovascular and all-cause mortality at 10 years after RDN.

Mechanisms and treatment of obesity-related hypertension-Part 1: Mechanisms

The prevalence of obesity has tripled over the past five decades. Obesity, especially visceral obesity, is closely related to hypertension, increasing the risk of primary (essential) hypertension by 65%-75%. Hypertension is a major risk factor for cardiovascular disease, the leading cause of death worldwide, and its prevalence is rapidly increasing following the pandemic rise in obesity. Although the causal relationship between obesity and high blood pressure (BP) is well established, the detailed mechanisms for such association are still under research. For more than 30 years sympathetic nervous system (SNS) and kidney sodium reabsorption activation, secondary to insulin resistance and compensatory hyperinsulinemia, have been considered as primary mediators of elevated BP in obesity. However, experimental and clinical data show that severe insulin resistance and hyperinsulinemia can occur in the absence of elevated BP, challenging the causal relationship between insulin resistance and hyperinsulinemia as the key factor linking obesity to hypertension. The purpose of Part 1 of this review is to summarize the available data on recently emerging mechanisms believed to contribute to obesity-related hypertension through increased sodium reabsorption and volume expansion, such as: physical compression of the kidney by perirenal/intrarenal fat and overactivation of the systemic/renal SNS and the renin-angiotensin-aldosterone system. The role of hyperleptinemia, impaired chemoreceptor and baroreceptor reflexes, and increased perivascular fat is also discussed. Specifically targeting these mechanisms may pave the way for a new therapeutic intervention in the treatment of obesity-related hypertension in the context of 'precision medicine' principles, which will be discussed in Part 2.

Effects of catheter-based renal denervation on renin-aldosterone system, catecholamines, and electrolytes: A systematic review and meta-analysis

In recent years, catheter-based renal denervation (RDN) has emerged as a promising instrumental therapy for hypertension. The interruption of sympathetic nervous system was regarded as a possible mechanism for RDN regulating blood pressure. While the results reflected by renin-angiotensin-aldosterone system (RAAS), catecholamines and electrolytes remained inconsistent and was never systematically assessed. Pubmed, Embase, and Web of Science were comprehensively searched from inception to September 5, 2021. Studies that evaluated the effects of RDN on RAAS, catecholamines, and electrolytes were identified. Primary outcomes were changes in RAAS hormones after RDN, and secondary outcomes involved changes in plasma norepinephrine, serum, and urinary sodium and potassium. Out of 6391 retrieved studies, 20 studies (two randomized controlled studies and 18 observational studies) involving 771 persons were eventually included. Plasma renin activity had a statistically significant reduction after RDN (0.24 ng/mL/h, 95% CI 0.04 to 0.44, P = .02). While no significant change was found regarding plasma aldosterone (1.53 ng/dL, 95% CI -0.61 to 3.67, P = .16), norepinephrine (0.42 nmol/L, 95% -0.51 to 1.35, P = 0.38), serum sodium and potassium (0.16 mmol/L, 95% CI -0.17 to 0.49, P = .34; -0.02 mmol/L, 95% CI -0.09 to 0.04, P = .48, respectively), and urinary sodium and potassium (3.95 mmol/24 h, 95% CI -29.36 to 37.26, P = .82; 10.22 mmol/24 h, 95% CI -12.11 to 32.54, P = .37, respectively). In conclusion, plasma renin activity significantly decreased after RDN, while no significant change was observed in plasma aldosterone, plasma norepinephrine, and serum and urinary electrolytes.