经皮经导管射频消融去肾交感神经术治疗难治性高血压消融阻抗与疗效的关系

Catheter-based renal sympathetic denervation in patients with resistant hypertension:a 2-year follow-up report and the correlation between impedance during ablating and efficacy

目的观察经皮经导管射频消融去肾交感神经术（RDN）对难治性（顽固性）高血压患者两年的降压效果及消融阻抗变化与疗效的关系。方法连续入选2011年10月至2013年3月中南大学湘雅三医院心内科连续收治的难治性高血压患者93例,其中6例因解剖原因排除（肾动脉为双支）,45例为手术组,行RDN,48例为对照组,继续药物治疗,记录消融前及消融时30、60、90及120s平均阻抗的变化,监测患者术前及术后1、3、6、12、18及24月的血压,术前及术后12月行多排CT肾动脉造影检查,评价手术的有效性与安全性及消融阻抗下降幅度对疗效的影响。结果手术组32例及药物组30例完成2年随访,手术组术后平均收缩压及平均舒张压均有不同程度的下降,随访1、3、6、12、18、24月平均收缩压分别下降（19.4±4.1）、（22.3±4.4）、（23.2±5.1）、（23.4±4.9）、（24.3±3.8）、（28.3±4.9）mm Hg,平均舒张压分别下降（9.5±1.5）、（10.4±1.6）、（11.4±1.9）、（13.5±1.5）、（13.6±1.4）、（14.1±1.5）mm Hg,与术前基线及对照组同期比较,差异有统计学意义（均P〈0.01）。随访24月有近50%的患者收缩压〈140mm Hg。手术组按阻抗降低幅度分为3个亚组,阻抗下降10~20Ω组及≥20Ω组的平均收缩压及平均舒张压下降幅度明显超过≤10Ω组（均P〈0.05）,10~20Ω及≥20Ω组间差异无统计学意义（P〉0.05）,7例无反应者中4例属于≤10Ω组。手术组术后血肌酐、肾小球滤过率与基线比较差异无统计学意义,多排CT肾动脉造影均未见肾动脉夹层及狭窄。结论 RDN能够显著和持久地降低难治性高血压患者的血压达到2年,手术安全有效,术中消融阻抗降低幅度〉10Ω可能与手术疗效相关。

Objective To explore the effect of renal sympathetic denervation（RDN）on blood pressure in patients with resistant hypertension,and the correlation between impedance during ablating and efficacy. Methods Initially93 patients with resistant hypertension were consecutively enrolled from October 2011 to March 2013 for this study,and of them 6patients were excluded due to anatomical reasons mainly based on dual renal artery systems. Fortyfive patients underwent RDN and 48 patients continued to receive drugs treatment as the controls. Office mean systolic and diastolic blood pressure（SBP and DBP）,serum creatinine and glomerular filtration rate（GFR）were measured before and 1,3,6,12,18,24 months after the procedure. Three-dimensional renal artery imaging and 64-detector CT renal arteriography were performed before and 12 months after the procedure. Results After 24-month follow-up,there were respectively 32 and 30patients in the procedure and control groups with complete data. After1,3,6,12,18 and 24 months of the procedure,office mean SBP and DBP were significantly reduced by 19.4（standard deviation：4.1）and 9.5（1.5）,22.3（4.4）and 10.4（1.6）,23.2（5.1）and 11.4（1.9）,23.4（4.9）and13.5（1.5）,24.3（3.8）and 13.6（1.4）,28.3（4.9）and 14.1（1.5）mm Hg,respectively,and these reductions were significant compared with their corresponding values at both baseline and in control group（P〈0.01）. About half of studied subjects had SBP lower than 140 mm Hg after the 24-month follow-up. The procedure group was further categorized into three subgroups according to the reduction magnitude of impedance during ablating. Mean SBP and DBP were obviously lower in the subgroups with both 10-20Ωand ≥20Ωreductions in impedance than subgroup with≤10Ωreduction（P〈0.05）,while no significance was attained between subgroups with 10-20and≥20Ωreductions（P〉0.05）. Of seven patients with no response,4had impedance reduced≤10Ω. Serum creatinine and GFR did not differ significantly in both procedure and control groups compared with their baseline values（P〉0.05）,and no renal artery dissection or stenosis was observed after 12 months of the procedure. Conclusion Catheter-based renal sympathetic denervation can cause substantial and sustained blood pressure reduction during the2-year follow-up,and there was a possible correlation between the reduced impedance of more than 10 Ωduring ablating and efficacy of RDN.