Feasibility of percutaneous coronary intervention before mitral NeoChord implantation: Single‐center early results

Abstract Background and Aim of the study Micro‐invasive cardiac surgery identifies procedures performed off‐pump, on beating heart. Aim of this single‐center retrospective study was to assess early outcomes of a totally micro‐invasive strategy (percutaneous coronary intervention—PCI—followed by transapical off‐pump NeoChord mitral repair) in patients with concomitant coronary artery disease (CAD) and degenerative mitral regurgitation (MR). Methods We analyzed early and 1‐year follow‐up data of patients who underwent a NeoChord procedure between November 2013 and May 2020, and preceded by PCI. Outcomes were defined according to Mitral Valve Academic Research Consortium (MVARC) definitions. Results Among 220 patients who underwent NeoChord repair in the study period, 17 (7.7%) underwent PCI previously. CAD was an accidental finding during preoperative mitral evaluation in nine patients (52.9%; Group 1; with PCI occurring 2 months before NeoChord, interquartile range [IQR] = 1.0–2.7), while it was part of the past medical history in the remaining eight patients (47.1%; Group 2; with PCI occurring 30 months before NeoChord, IQR = 24.5–64.0). Twelve patients (70.6%) presented single‐vessel disease, two patients (11.8%) triple‐vessel disease. No surgical revisions for bleeding were required after NeoChord. At 1‐year follow‐up (n = 16), all patients were alive and did not experience major adverse events except for one reoperation due to late NeoChord failure. None required additional PCI. Conclusion In our experience, PCI before NeoChord seems safe and effective, and performing PCI before NeoChord might not affect outcomes. A totally micro‐invasive strategy in selected patients suffering from MR and CAD should be considered as a reasonable alternative to conventional surgery.


| INTRODUCTION
Recently, the new concept of micro-invasive cardiac surgery has been introduced to identify procedures performed off-pump, on beating heart (e.g., transcatheter aortic valve replacement, transcatheter mitral valve repair or replacement). 1,2 Mitral valve repair can be performed either with open-heart procedures (full sternotomy or minimally invasive cardiac surgery) or through micro-invasive transapical neochordae implantation. The former has shown well-established early and long-term results, while the latter has demonstrated promising early and 5-year outcomes. 3 Although open-heart cardiac surgery remains the gold standard for patients with combined coronary artery disease (CAD) and mitral regurgitation (MR), a totally micro-invasive strategy (percutaneous coronary intervention-PCI-+NeoChord) might allow to optimize outcomes especially in selected patients.
In the present single-center, retrospective study, we aimed to analyze the early clinical outcomes of PCI followed by transapical offpump NeoChord mitral valve repair in patients with CAD and degenerative MR.

| MATERIALS AND METHODS
Among all patients who underwent a NeoChord mitral repair procedure at the Padova University Hospital, we retrospectively analyzed early and 1-year clinical and echocardiographic outcomes of those subjects who also underwent a previous PCI.
All enrolled patients had indications for surgical mitral repair due to degenerative MR according to current guidelines. 4 Functional MR cases were excluded.
The choice to perform a NeoChord mitral repair was based on the following anatomical criteria: a mitral tissue overlap to obtain a potential postoperative coaptation length of 3-5 mm and the leafletto-annulus index (LAI) with a cutoff value of >1.25; the "surgically derived" morphological classification which includes four anatomical types (type A: isolated central posterior leaflet prolapse/flail; type B: posterior multisegment prolapse/flail; type C: anterior, bileaflet, or paracommissural disease; type D: leaflet and/or annular calcifications); cases showing mitral annular calcifications were excluded. 5 All patients gave their informed consent for the procedure and for data collection for scientific purposes. Data collection of Neo-Chord procedures has been approved by the local Ethical Committee 2.1 | Indications to PCI, PCI procedure, and NeoChord technique PCI was performed according to the current guidelines. 8,9 Dual antiplatelet therapy (DAPT) had been started in each patient at the time of PCI, and continued for at least 6 months after the coronary procedure. 10,11 PCI was performed through a femoral or radial artery access.   (Table 3).  None of the patients presented acute coronary syndromes or ischemic symptoms, and none required coronary reintervention.

| DISCUSSION
The main finding of the present study is that a total micro-invasive strategy for selected patients with associated CAD and MR is safe and effective.
Furthermore, a history of PCI before NeoChord mitral repair, regardless of timing, does not affect post-procedural outcomes. In fact, there are no differences in terms of postoperative morbidity and mortality as well as 1-year follow-up outcomes between the two groups.
According to STS adult cardiac surgery database, traditional surgical mitral repair shows 1.1% mortality, which increases to 6.2% when associated with CABG. 11 For this reason, intraoperative and postoperative risks related to combined mitral and CAD surgery may be reduced by favoring lower-risk procedures such as PCI and microinvasive mitral repair techniques in selected patients.
Among different mitral repair strategies for patients who present degenerative MR, the micro-invasive off-pump NeoChord mitral repair has shown to be a safe, and reproducible technique, with good outcomes at discharge, and clinical efficacy maintained up to 5 years of follow-up. 12,13 In the setting of CAD and mitral valve disease, the less invasive strategy of PCI followed by minimally invasive valve surgery has also demonstrated positive early and midterm results. 14,15 However, these recent works have not considered micro-invasive mitral procedures, which constitute a rapidly expanding field, and have the potential of being adopted as a valuable alternative to conventional or minimally invasive surgery in selected patients. 16 Patient selection is crucial to understand who will benefit from these techniques. Regarding the NeoChord procedure, several echocardiographic parameters (LAI, morphological classification, and length of coaptation prediction index) have been introduced to help to standardize preoperative selection. The most recent evidence shows that NeoChord repair can be a reasonable alternative to conventional surgery for a subset of patients with MR in an early phase when the disease is limited to the leaflets and not extended to the annulus and/or to the left ventricle. 12 In this study, the procedures were performed by the same operator (Gino Gerosa) and all cases were performed after the initial 40 cases (recognized by the CUSUM analysis as the threshold to standardize the procedure in all its technical aspects). 17 In our cohort, a micro-invasive treatment strategy resulted satisfactory in terms of reduced blood transfusions, reduced ventilation, and hospitalization times.
STS database demonstrates not only a higher mortality (6.2%) in patients undergoing MV repair and CABG, but also a significant higher rate of major bleedings (5.5%) and stroke (2.8%) than those observed in the present report. 18 In patients with the previous PCI, undergoing minimally invasive mitral valve repair, Santana et al. 15 showed promising outcomes in terms of postoperative cerebrovascular accident (1.1%), acute kidney MR ≤ mild at discharge 9 (100%) 7 (87.5%) .27 Note: variables are expressed as number of patients, n and percentages, %, or mean ± SD.