Transcatheter mitral edge-to-edge repair in oncology patients: insights from the Spanish M-TEER registry

Background Transcatheter edge-to-edge repair (M-TEER) is a safe and effective therapy for mitral regurgitation (MR). Patients with prior cancer diagnosis are at increased risk of MR due to cardiotoxic treatment exposure but were underrepresented in landmark M-TEER trials. This study aimed to evaluate the efficacy and safety of M-TEER in patients with a history of cancer. Methods We conducted a retrospective, multicenter observational study using the Spanish M-TEER registry (Figure 1A). Patients with and without a history of cancer were matched 1:1 using propensity score matching (PSM). The primary endpoint was a composite of all-cause mortality or unplanned heart failure hospitalization at mid-term follow-up. Results A total of 1,237 patients (mean age 73±11 years, 34% female) underwent M-TEER between 2012 and 2022 across 14 centers in Spain. Of these, 164 (13%) had a prior cancer diagnosis, a proportion that increased over time (Mann-Kendall p=0.048, Figure 1B). The median time from cancer diagnosis to M-TEER was 7 years (IQR: 3-17). The most common malignancies were breast (21%), leukemia/lymphoma (20%), and colorectal (12%). MR etiology was associated with cancer type (p<0.001, Figure 1C). After PSM, the 163 matched pairs showed well-balanced baseline characteristics (Figure 2). Technical success was similarly high in both groups (cancer vs. control: 97% vs. 98%, p=0.999), as was device success (88% vs. 90%, p=0.591). At a median follow-up of 24 months (IQR: 11-43), the primary endpoint occurred in 80 (49.1%) patients in the cancer group and 69 (42.3%) in the control group (HR: 1.23, 95% CI 0.89–1.70, p=0.202). Although patients with functional MR had a higher risk of the primary endpoint compared to those with organic or mixed MR (HR: 1.43, 95% CI 1.03–2.00, p=0.036), there was no significant interaction between MR etiology and cancer status (pint=0.516). At 1 year, MR grade II or lower was observed in 85.8% of cancer patients and 86.5% of controls (p=0.889). Functional status also improved significantly in both groups, with 80.0% of cancer patients and 80.2% of controls in NYHA class I or II (p=0.974, both p<0.001 vs. baseline). Conclusion In this multicenter Spanish cohort, M-TEER showed comparable periprocedural and mid-term outcomes in patients with and without a history of cancer. These findings suggest that M-TEER should be considered in this growing and often challenging population.