Outcomes after transcatheter aortic valve replacement in cancer survivors with prior chest radiation therapy: a systematic review and meta-analysis

BACKGROUND: Cancer survivors with prior chest radiation therapy (C-XRT) frequently present with aortic stenosis (AS) as the first manifestation of radiation-induced heart disease. They are considered high-risk for surgical valve replacement. Transcatheter aortic valve replacement (TAVR) is as an attractive option for this patient population but the outcomes are not well established in major clinical trials. The authors performed a systemic review and meta-analysis of clinical studies for the outcomes after TAVR in cancer survivors with prior C-XRT. METHODS: Online databases were searched from inception to April 2020 for studies evaluating the outcomes of TAVR in patients with and without C-XRT. We analyzed the pooled estimates (with their 95% confidence intervals) of the odds ratio (OR) for the all-cause mortality at 30-day and 1-year follow-ups, 4-point safety outcomes (stroke, major bleed, access-related vascular complications and need for a pacemaker), a 2-point efficacy outcome (mean aortic valve gradient and left ventricular ejection fraction) and worsening of congestive heart failure (CHF). Four studies were included following 2054 patients with and without prior C-XRT exposure (164 patients and 1890 patients respectively). RESULTS: The C-XRT group had similar 30-day mortality compared to the control group (OR 1.29, 95% CI 0.64 to 2.58, p = 0.48). The 1-year mortality was higher in the C-XRT group (OR 1.97, CI 1.15 to 3.39, p = 0.01). Apart from higher congestive heart failure (CHF) exacerbation in the C-XRT group (OR 2.03, CI 1.36 to 3.04, p = 0.0006), TAVR resulted in similar safety and efficacy outcomes in both groups. CONCLUSION: TAVR in the C-XRT group has similar 30-day mortality, safety, and efficacy outcomes compared to the control group; however, they have higher 1-year mortality and CHF exacerbation. Including an oncologist to the cardiology team who considers cancer stage in the decision-making process and applying additional preoperative scores such as frailty indices may refine the risk assessment for these patients. The quality of analyzed data is modest, warranting randomized trials to assess the true benefits of TAVR in these patients.