Renal denervation restores autonomic imbalance and prevents atrial fibrillation in patients with hypertensive heart disease : a pilot study
Thesis (PhD)--Stellenbosch University, 2020.
ENGLISH ABSTRACT: Background: Atrial fibrillation (AF) is associated with increased cardiovascular morbidity and mortality, but it is uncertain if catheter-based renal denervation (RD) can reduce AF in patients with hypertensive heart disease (HHD). Methods: Patients who were ≥ 55 years old, in sinus rhythm, taking ≥ 3 anti-hypertensive drugs including a diuretic, with echocardiogram-confirmed HHD and suspected coronary artery disease, were randomised to undergo RD or sham procedure. Patients with renal impairment, significant valvular heart disease and untreated thyroid disease were excluded. The primary endpoint, the first episode of subclinical AF (SAF) lasting ≥ 6 minutes, was detected using an implantable loop recorder which was scanned every six months. Six-month follow-up (6MFU) office systolic blood pressure (SBP), cardiovascular mortality and restoration of autonomic imbalance were secondary endpoints. Results: Eighty patients were randomised: 42 underwent RD and 38 a sham procedure. After an average follow-up of three years, fewer RD patients experienced SAF: 6 of 42 patients (14.3%) vs 15 of 38 (39.5%) sham patients (odds ratio (OR), 0.26; 95% CI, 0.1 to 0.71, p = 0.01). Fast AF (ventricular rate ≥ 100 bpm) occurred in 10 sham patients (26.3%) vs 1 RD patient (2.4%): OR, 14.64; 95% CI, 1.77 to 120.91; p = 0.002). The incidence of cardiovascular death was higher in the sham than RD group (6 of 38 (15.8%) vs 1 of 42 (2.4%): OR, 7.69; 95% CI, 0.88 to 67.12; p = 0.049). Non-ST elevation myocardial infarction (NSTEMI) incidence was lower in the RD than sham group (2.3% vs 18.4%: OR, 0.108; 95% CI, 0.01–0.92; p = 0.02). The 6MFU between-group SBP difference was not significant (−3.8 mmHg; p = 0.49). Resting and one-minute recovery heart rate did not differ between groups at 6MFU. Conclusion: In patients with HHD, RD reduces subclinical and fast AF, NSTEMI and cardiovascular death independent of lowering blood pressure. RD was not associated with improvement of surrogate markers of autonomic imbalance.