Purpose

We present the preliminary results of the STRA-MI-VT Study (NCT04066517), a spontaneous, phase Ib/II study, designed to prospectively test the safety and efficacy of stereotactic body radiotherapy (SBRT) in patientswith advanced cardiac disease and intractable ventricular tachycardia (VT).

Methods

Cardiac computed tomography (CT) integrated by electroanatomical mapping was used for substrate identification and merged with dedicated CT scans for treatment plan preparation. A single 25-Gy radioablation dose was delivered by a LINAC-based volumetric modulated arc therapy technique in a non-invasive matter. The primary safety endpoint was treatment-related adverse effects during acute and long-term follow-up (FU), obtained by regular in-hospital controls and implantable cardioverter defibrillator (ICD) remote monitoring. The primary efficacy endpoint was the reduction at 3 and 6 months of VT episodes and ICD shocks.

Results

Seven out of eight patients (men; age, 70 ± 7 years; ejection fraction, 27 ± 11%; 3 ischemic, 4 non-ischemic cardiomyopathies) underwent SBRT. At a median 8-month FU, no treatment-related serious adverse event occurred. Three patients died from non-SBRT-related causes. Four patients completed the 6-month FU: the number of VT decreased from 29 ± 33 to 11 ± 9 (p = .05) and 2 ± 2 (p = .08), at 3 and 6 months, respectively; shocks decreased from 11 to 0 and 2, respectively. At 6 months, all patients. showed a significant reduction of VT episodes and no electrical storm recurrence, with the complete regression of iterative VTs in 2/2 patients.

Conclusion

The STRA-MI-VT Study suggests that SBRT can be considered an alternative option for the treatment of VT in patients with structural heart disease and highlights the need for further clinical investigation addressing safety and efficacy.

中文翻译：

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立体定向放射消融治疗室性心动过速：来自 STRA-MI-VT Ib/II 期研究的初步数据和见解

目的

我们展示了 STRA-MI-VT 研究 (NCT04066517) 的初步结果，这是一项自发的 Ib/II 期研究，旨在前瞻性地测试立体定向放疗 (SBRT) 在晚期心脏病和顽固性室性心动过速患者中的安全性和有效性(VT)。

方法

通过电解剖标测集成的心脏计算机断层扫描 (CT) 用于基底识别，并与专用 CT 扫描合并以准备治疗计划。单次 25-Gy 放射消融剂量是通过基于 LINAC 的容积调制弧治疗技术以非侵入性方式提供的。主要安全终点是急性和长期随访 (FU) 期间与治疗相关的不良反应，通过定期住院控制和植入式心律转复除颤器 (ICD) 远程监测获得。主要疗效终点是 3 个月和 6 个月时 VT 发作和 ICD 电击的减少。

结果

八名患者中有七名（男性；年龄，70 ± 7 岁；射血分数，27 ± 11%；3 名缺血性心肌病，4 名非缺血性心肌病）接受了 SBRT。在中位 8 个月的 FU 中，没有发生与治疗相关的严重不良事件。三名患者死于非 SBRT 相关的原因。4 名患者完成了 6 个月的 FU： 在 3 个月和 6 个月时，VT 的数量分别从 29 ± 33 减少到 11 ± 9 ( p  = .05) 和 2 ± 2 ( p = .08)；冲击分别从 11 减少到 0 和 2。在 6 个月时，所有患者。显示 VT 发作显着减少且无电风暴复发，2/2 患者的迭代 VT 完全消退。

结论

STRA-MI-VT 研究表明 SBRT 可被视为治疗结构性心脏病患者 VT 的替代选择，并强调需要进一步临床研究以解决安全性和有效性问题。