In Vivo Analysis of the Anatomical Relationship of Coronary Sinus to Mitral Annulus and Left Circumflex Coronary Artery Using Cardiac Multidetector Computed Tomography

Clinical anatomy of the coronary venous system and relevance to retrograde cardioplegia and cardiac electrophysiological interventions

Anomalies of coronary venous system, the valve of the coronary sinus (Thebesian valve) and other cardiac malformations may make interventions through the coronary sinus difficult. These variants may pose a challenge in cannulating the coronary sinus for retrograde cardioplegia and for interventions performed through the coronary sinus by cardiac electrophysiologist/interventional cardiologist. Retrograde cardioplegia is an established method of myocardial protection with advantages, indications, and complications. A good knowledge of the anatomy of the coronary sinus and its variants is important in understanding the difficulties encountered while cannulating the coronary sinus for the delivery of retrograde cardioplegia, cardiac resynchronization therapy, treatment of arrhythmias, and percutaneous mitral valve annuloplasty.

The Effect of Medial Circumflex Artery Variation on the Success Rate of Gracilis Flap Procedures: A Systematic Review

This systematic review examines the impact of anatomical variations in the medial circumflex artery (MCA) on the outcomes of gracilis flap procedures in reconstructive surgery. Incorporating 16 studies, this review analyzes how different MCA variants influence the success rates of these procedures. Findings highlight critical MCA variations, including cases of split and double pedicles and differences in pedicle length and branching patterns, which can complicate flap harvesting and vascular anastomosis. The studies consistently underscore the need for precise preoperative imaging and intraoperative adaptability to manage these anatomical differences effectively.  Notably, variants with shorter or branched pedicles present higher risks of partial flap loss and complications, particularly in autologous breast reconstruction and lower extremity repairs. The findings support the adoption of advanced imaging protocols, such as high-resolution Doppler and CT angiography, to enable detailed vascular mapping. Interdisciplinary collaboration among anatomists, radiologists, and surgeons is essential for developing comprehensive strategies tailored to individual anatomical landscapes, optimizing both the success and viability of gracilis flaps.  The review emphasizes that understanding MCA variability is crucial for enhancing surgical precision and improving patient outcomes. Standardizing preoperative assessment protocols and exploring alternative flap techniques may mitigate risks associated with MCA variations, advancing the field of reconstructive surgery.

Transcatheter Mitral Annuloplasty: Carillon Device

Functional mitral regurgitation (FMR) is a common valvular heart disease in the geriatric population across the United States. This patient cohort is multimorbid and often has a prohibitive risk for conventional open-heart surgery. The diverse anatomic pathology of FMR is a complex problem and unfortunately does not have a universal solution. Carillon Mitral Contour System (Cardiac Dimensions, Kirkland, WA, USA) is a new device that provides transcatheter annular remodeling. In this review article, the authors summarize the evidence for the Carillon Mitral Contour System for FMR.

Heart Failure and Secondary Mitral Regurgitation: A Contemporary Review

Secondary mitral regurgitation (SMR) in patients with heart failure (HF) is associated with significant morbidity and mortality. In recent decades, SMR has received increasing scientific attention. Advances in echocardiography, computed tomography and cardiac magnetic resonance imaging have refined our ability to diagnose, quantify and characterize SMR. Concurrently, the treatment options for this high-risk patient population have continued to evolve. Guideline-directed medical therapies including beta-blockers, angiotensin receptor-neprilysin inhibitors, mineralocorticoid receptor antagonists and sodium-glucose cotransporter-2 inhibitors target the underlying cardiomyopathy, and along with diuretics to treat pulmonary congestion, remain the cornerstone of therapy. Cardiac resynchronization therapy also reduces MR, alleviates symptoms and prolongs life in selected HF patients with SMR. While data supporting surgical mitral valve repair or replacement for SMR are limited, transcatheter edge-to-edge repair (TEER) has been demonstrated to improve survival, reduce the rate of hospitalization for heart failure, and improve functional capacity and quality-of-life in select patients with SMR who remain symptomatic despite medical therapy. Emerging transcatheter mitral valve repair and replacement technologies are undergoing investigation in TEER-eligible and TEER-ineligible patients. The optimal management of HF patients with SMR requires a multidisciplinary team of cardiologists, cardiac surgeons, imaging experts, and other organ specialists to select the best treatment approaches to improve the prognosis of these high-risk patients.

Multimodality imaging for patient selection, procedural guidance, and follow-up of transcatheter interventions for structural heart disease: a consensus document of the EACVI Task Force on Interventional Cardiovascular Imaging: part 1: access routes, transcatheter aortic valve implantation, and transcatheter mitral valve interventions

Transcatheter therapies for the treatment of structural heart diseases (SHD) have expanded dramatically over the last years, thanks to the developments and improvements of devices and imaging techniques, along with the increasing expertise of operators. Imaging, in particular echocardiography, is pivotal during patient selection, procedural monitoring, and follow-up. The imaging assessment of patients undergoing transcatheter interventions places demands on imagers that differ from those of the routine evaluation of patients with SHD, and there is a need for specific expertise for those working in the cath lab. In the context of the current rapid developments and growing use of SHD therapies, this document intends to update the previous consensus document and address new advancements in interventional imaging for access routes and treatment of patients with aortic stenosis and regurgitation, and mitral stenosis and regurgitation.

Cardiac computed tomography based analysis of mitral annulus, coronary sinus and left circumflex artery in patients with mitral regurgitation: Implications for transcatheter mitral annuloplasty techniques

INTRODUCTION

CT imaging analysis of mitral annulus (MA), coronary sinus (CS) and left circumflex artery (LCX) is critical to transcatheter mitral annuloplasty (TMA), which, however, is scantly reported. We aimed to comprehensively assess MA, CS and LCX anatomy and geometry in mitral regurgitation (MR) based on 3-D reconstruction of cardiac CT images.

METHODS

Patients with primary or secondary MR and patients without MR were recruited and underwent cardiac CT examination. MR severity was evaluated by echocardiography. 3-D reconstruction of cardiac CT images was done by the Mimics Research 21.0 software. A MA-centered two dimensional coordinate system, a CS plane, a MA plane and a series of auxiliary planes along the posterior MA were created for the measurement of parameters defining MA, CS and LCX anatomy and geometry during the cardiac cycle.

RESULTS

The secondary MR group had a significantly higher MA perimeter index than the other two groups during the cardiac cycle. The CS diameters at most sites, and the posterior MA radian were substantially greater in the two MR groups. Distances between the CS and MA at some locations were significant different among the three groups. The secondary MR group had a significantly smaller CS-MA plane angle than the other two groups during systole, and than control group during diastole. The site where the CS crossed LCX was pinpointed.

CONCLUSION

The comprehensive information from this study may help improve the results of TMA and enhance the design of devices for a better annuloplasty effect.

Transcatheter Coronary Sinus Interventions

The coronary sinus has become a popular route for an increasing number of innovative transcatheter interventions to treat coronary and structural heart diseases. However, interventional cardiologists have limited experience with the cardiac venous system and its highly variable anatomy. In this paper, we review the anatomy of the cardiac veins as it relates to transcatheter interventions. We also provide a contemporary overview of the emerging coronary sinus-based transcatheter therapies and their growing literature.

Anatomy and Topography of Coronary Sinus and Mitral Valve Annulus in Functional Mitral Regurgitation

Background

We aimed to investigate the anatomical relationship of the coronary sinus (CS) and the mitral valve annulus (MVA) in patients with or without functional mitral regurgitation (FMR) using a multislice CT (MSCT) software to determine (a) the distance and angle of both CS and MVA plane and (b) the mitral annulus geometry.

Methods

A total of 215 patients with MSCT and CS to MVA topography evaluation were enrolled in this retrospective study.

Results

This patient cohort included 145 patients without FMR (67.4%, FMR ≤ 1+) and 70 patients (32.6%) with clinically relevant FMR (FMR ≥ 2+). Distance and angulation of CS to MVA planes were highly variable. In all groups, no significant correlation was documented between the distance or angle of CS to MVA planes and left ventricular ejection fraction, left ventricular end-diastolic diameter, or left atrial volume. A significant increase in total CS length could be found in patients with FMR ≥ 2+ compared to the FMR ≤ 1+ group. MVA diameter, area, and perimeter were significantly increased in FMR ≥ 2+ compared to FMR ≤ 1+. In the FMR ≥ 2+ cohort 61% showed a distance of CS to MVA plane <7.8 mm and 58% revealed an angle of CS to MVA plane <14.2°.

Conclusion

Distance and angulation of CS to MVA topography using an MSCT approach are similar between patients with or without FMR, while CS length, MVA area, MVA perimeter, anterior-posterior diameter, and intercommissural diameter are significantly increased in all FMR subgroups. However, ~60% of FMR ≥ 2+ patients showed favorable CS to MVA topography for indirect mitral annuloplasty.

Restructuring the Heart From Failure to Success: Role of Structural Interventions in the Realm of Heart Failure

Heart failure through the spectrum of reduced (HFrEF), mid-range (or mildly reduced or HFmEF), and preserved ejection fraction (HFpEF), continues to plague patients' quality of life through recurrent admissions and high mortality rates. Despite tremendous innovation in medical therapy, patients continue to experience refractory congestive symptoms due to adverse left ventricular remodeling, significant functional mitral regurgitation (FMR), and right-sided failure symptoms due to significant functional tricuspid regurgitation (FTR). As most of these patients are surgically challenging for open cardiac surgery, the past decade has seen the development and evolution of different percutaneous structural interventions targeted at improving FMR and FTR. There is renewed interest in the sphere of left ventricular restorative devices to effect reverse remodeling and thereby improve effective stroke volume and patient outcomes. For patients suffering from HFpEF, there is still a paucity of disease-modifying effective medical therapies, and these patients continue to have recurrent heart failure exacerbations due to impaired left ventricular relaxation and high filling pressures. Structural therapies involving the implantation of inter-atrial shunt devices to decrease left atrial pressure and the development of implantable devices in the pulmonary artery for real-time hemodynamic monitoring would help redefine treatment and outcomes for patients with HFpEF. Lastly, there is pre-clinical data supportive of soft robotic cardiac sleeves that serve to improve cardiac function, can assist contraction as well as relaxation of the heart, and have the potential to be customized for each patient. In this review, we focus on the role of structural interventions in heart failure as it stands in current clinical practice, evaluate the evidence amassed so far, and review promising structural therapies that may transform the future of heart failure management.

Transcatheter Mitral Valve-in-Valve Implantation in Pediatric Patients

BACKGROUND

Transcatheter implantation of the Edwards Sapien 3 valve (Edwards Lifesciences, Irvine CA) within the bioprosthetic mitral valve (MV) is an established method of treatment in adults. However, it has not been well studied in the pediatric age group.

METHODS

Transcatheter mitral valve-in-valve implantation was attempted in 4 symptomatic pediatric patients with a dysfunctional MV bioprosthesis implanted at an earlier stage due to severe MV stenosis or regurgitation. We reviewed our experience with MV implantation in this cohort.

RESULTS

The mean age and weight of the patients at the time of the procedure were 11.4 years (range: 10-14 years) and 36 kg (range: 31-44 kg), respectively. The transmitral mean gradient dropped from a mean of 19.75 mm Hg (range: 15-22 mm Hg) to a mean of 1 mm Hg (range: 0-3 mm Hg) after the procedure. The mean fluoroscopy time was 55.25 minutes (range: 40-72 minutes), and the mean hospital length of stay was 4 days (range: 3-7 days). The patients' functional class improved from New York Heart Association class IV to class I during the follow-up period.

CONCLUSIONS

Transcatheter mitral valve-in-valve implantation can be performed safely for dysfunctional bioprosthetic MVs in the pediatric age group with favorable early and midterm outcomes. This procedure offers a viable alternative in patients who have high surgical risk or are deemed unfit for conventional surgery. However, we still recommend a long-term study of this approach in a large cohort, multicentre study.

Procedural planning of CS-based indirect mitral annuloplasty using CT-angiography

OBJECTIVES

Coronary sinus (CS) based mitral annuloplasty using the Carillon device could be limited by compromise of the left circumflex artery (Cx).

BACKGROUND

Computed tomography (CT) might be a feasible tool for preprocedural planning of indirect mitral valve annuloplasty.

METHODS

In a retrospective analysis, 25 patients underwent Carillon device implantation and received CT-angiography (CTA) analysis prior to CS based percutaneous mitral valve repair. We used a retrospective approach with preprocedural CTA and intraprocedural coronary sinus angiography (CSA) measurements to determine the CS to Cx distance at the occlusion or compression point or in the distal landing zone in absence of Cx compromise.

RESULTS

According to left coronary artery angiography, we identified 7 patients with Cx occlusion, 7 with Cx compression and 11 without Cx compromise. No difference in minimal CS to Cx distance between the three groups could be obtained. Also, neither distal CS diameter nor distal Carillon anchor size were related to Cx impingement. However, ROC analysis identified a CS to Cx distance of <8.6 mm specifically in the distal device landing zone to predict Cx compromise. Furthermore, CTA was accurate in assessing device length in comparison to CSA, but failed predicting Carillon device anchor size.

CONCLUSIONS

CTA derived CS to Cx distance in the device landing zone might be helpful to predict Cx occlusion during Carillon device implantation. Furthermore, CTA predicted CS length but not anchor size correctly. Therefore, CT-angiographic procedural planning might help improving the results of percutaneous CS-based mitral valve repair.

Indirect Mitral Annuloplasty Using the Carillon Device

Patients with functional, or secondary, mitral regurgitation (FMR, SMR) often face significant symptoms that lead to functional decline as well as hospitalization and even death. Traditional mitral annuloplasty is an important treatment option for patients with FMR, but surgical risk and durability are important limitations. Percutaneous strategies are therefore a welcome alternative. The Carillon device utilizes the relationship of the coronary sinus and the mitral annulus to effect an “indirect” annuloplasty. Early series' and recent randomized trials suggest echocardiographic and clinical benefit with a relatively straight-forward implantation technique and low rate of significant complications.

Cardiac CT angiography: normal and pathological anatomical features-a narrative review

The normal and pathological anatomy of the heart and coronary arteries are nowadays widely developed topics and constitute a fundamental part of the cultural background of the radiologist. The introduction of cardiac ECG-gated synchronized CT scanners with an ever-increasing number of detectors and with increasingly high structural characteristics (increase in temporal resolution, increase in contrast resolution with dual-source, dual energy scanners) allows the virtual measurement of anatomical in vivo structures complying with heart rate with submillimetric precision permitting to clearly depict the normal anatomy and follow the pathologic temporal evolution. Accordingly to these considerations, cardiac computed tomography angiography (CCTA) asserts itself as a gold standard method for the anatomical evaluation of the heart and permits to evaluate, verify, measure and characterize structural pathological alterations of both congenital and acquired degenerative diseases. Accordingly, CCTA is increasingly used as a prognostic model capable of modifying the outcome of diseased patients in planning interventions and in the post-surgical/interventional follow-up. The profound knowledge of cardiac anatomy and function through highly detailed CCTA analysis is required to perform an efficient and optimal use in real-world clinical practice.

Successful trans-septal ablation of a left concealed accessory pathway in a patient receiving surgical mitral valve repair and mechanical aortic valve replacement

We presented a case of severe aortic regurgitation and moderate mitral regurgitation s/p aortic valve replacement and mitral valve repair. Deterioration of tachyarrhythmia attacks was noted. In EP study, left lateral accessory pathway with orthodromic atrioventricular reentrant tachycardia was identified. We successfully ablated the accessory pathway by trans‐septal approach. Even though trans‐septal approach currently is a daily routine of invasive interventional electrophysiologists, in this case, we want to emphasize and illustrate the distance between true mitral annulus and coronary sinus. Unrecognizing this concept could result in efficacy and safety of catheter‐based therapy.

Mitral valve annulus and circumflex artery: In vivo study of anatomical zones

Objective

To provide, with the use of preoperative coronary computed tomography angiography, an in vivo anatomical characterization of the relationship between the circumflex artery and mitral valve annulus to identify different risk classes and to increase the surgical awareness of those anatomical relations.

Methods

Ninety-five (mean age: 64.2 ± 11.7) consecutive patients, initially referred for elective minimally invasive mitral valve surgery, underwent preoperative coronary computed tomography angiography. The distance between the circumflex artery and mitral annulus was assessed using 6 points designed on the posterior mitral annulus, starting from the anterolateral to the posteromedial commissure; this design created an ideal 5-zone system. High-risk anatomy was defined as a distance less than 3 mm between the circumflex artery and the mitral valve annulus.

Results

The shortest distance between the circumflex artery and mitral valve annulus was observed at the area between the anterolateral commissure and the midpoint of P1 scallop, so-called zone 1 (5.49 ± 3.13 mm), whereas the longest distance occurred at zone 5 (12.03 ± 4.93). Twenty-four patients (25%) were identified with high-risk anatomy (mean distance 1.94 ± 0.8 mm). Left dominant and co-dominant hearts demonstrated a shorter circumflex artery-mitral valve annulus distance at all the zones. At multinomial logistic regression, the pattern of coronary dominance and the size of the circumflex artery were independent factors for high-risk anatomy.

Conclusions

Coronary computed tomography angiography is a useful investigation to identify patients at risk of circumflex artery flow disturbance; for high-risk anatomy, this knowledge may enhance a safer operative technique.

CT-Angiography to predict outcome after indirect mitral annuloplasty in patients with functional mitral regurgitation

OBJECTIVES

Coronary sinus (CS) based mitral annuloplasty using the Carillon device is effective in reducing functional mitral valve regurgitation (FMR). However, this positive effect might be dependent on the relation between CS and the mitral annulus.

BACKGROUND

Computed tomography (CT) assessment prior to mitral valve interventions is an emerging technique to optimize patient selection.

METHODS

In a retrospective analysis 30 patients underwent Carillon device implantation and received CT-angiography prior to CS based percutaneous mitral valve repair. Patients were assigned to responders or non-responders according to the 3-month transthoracic echocardiographic follow-up including quantitative mitral valve regurgitation assessment. A prototype software for CS reconstruction was used to assess distance and angle of both CS and mitral annulus planes.

RESULTS

Comparison of the distance and angle of the CS plane and the mitral valve annulus plane showed a significant shorter distance and lower angle in the responder group implicating an impact on procedure success. Our results suggest a CS plane and MV annulus plane with a favorably distance of <7.8 mm and an optimal angle of <14.2° could be considered favorably for mitral annuloplasty using a Carillon device.

CONCLUSIONS

Distance and angle of mitral annulus and CS planes determined by three-dimensional reconstructions of CT-angiography might predict a reduction in echocardiographic FMR using Carillon Mitral Contour System.

Complications Following Percutaneous Mitral Valve Repair

Mitral valve disease affects more than 4 million people in the United States and it is the second most prevalent valvulopathy in Europe. The gold standard of treatment in these patients is surgical repair or mitral valve replacement. In the last decade, numerous transcatheter therapies have been developed to overcome the increased number of subjects with symptomatic severe mitral regurgitation and high surgical risk. The Mitraclip (Abbott Vascular, Menlo Park, CA), PASCAL (Edwards Lifesciences, Irvine, CA, USA), the Carillon™ Mitral Contour System™ (Cardiac Dimension Inc., Kirkland, WA, USA), the Mitralign™ (Mitralign, Tewksbury, Massachusetts), and the Cardioband (Edwards Lifesciences, Irvine, CA) are the principal percutaneous devices for mitral valve repair. We present an evidence-based clinical update that provides an overview of these technologies and their potential complications.

Indirect Annuloplasty to Treat Functional Mitral Regurgitation: Current Results and Future Perspectives

The incidence of mitral regurgitation (MR) is approximately 1.7% in the developed world, and this increases to more than 10% in patients aged over 75 years. Functional (or secondary) mitral regurgitation (FMR) is defined as poor leaflet coaptation and tethering secondary to either ischemic or non-ischemic left ventricular (LV) dysfunction and dilatation. FMR is more common than degenerative (or primary) MR and is associated with significantly worse outcomes in patients with heart failure, post myocardial infarction and following coronary artery bypass graft surgery. Patients with severe degenerative MR have excellent outcomes with surgical repair, however the benefits of surgery in FMR are less clear. Although annuloplasty is associated with a lower operative mortality compared to replacement, the recurrence rate of mitral regurgitation is high in patients with FMR and neither surgical repair or replacement have been shown to reduce hospitalisation or death in FMR. Furthermore, nearly half of patients are deemed too high risk for surgery and therefore most patients are managed conservatively and there remains an unmet clinical need. Transcatheter mitral valve interventions are an emerging alternative for those at high surgical risk. This mini review focuses on indirect mitral annuloplasty: anatomical considerations, patient selection, current devices, implantation techniques and the associated clinical outcome data.

Mitral Loop Cerclage Annuloplasty for Secondary Mitral Regurgitation: First Human Results

OBJECTIVES

This is an early feasibility clinical test of mitral loop cerclage annuloplasty to treat secondary mitral valve regurgitation.

BACKGROUND

Secondary mitral regurgitation is characterized by cardiomyopathy, mitral annular enlargement, and leaflet traction contributing to malcoaptation. Transcatheter mitral loop cerclage applies circumferential compression to the mitral annulus by creating a loop through the coronary sinus across the interventricular septum, protecting entrapped coronary arteries from compression, and interactive annular reduction under echocardiographic guidance. This is the first human test of mitral loop annuloplasty.

METHODS

Five subjects with severe symptomatic secondary mitral regurgitation underwent mitral loop cerclage, with echocardiographic and computed tomography follow-up over 6 months.

RESULTS

Mitral loop cerclage was successful in 4 of 5 subjects and aborted in 1 of the 5 because of unsuitable septal coronary vein anatomy. Immediately and over 6 months, measures of both mitral valve regurgitation (effective orifice area and regurgitation fraction) and chamber dimensions (left atrial and left ventricular volumes) were reduced progressively and ejection fractions increased. Two with persistent and permanent atrial fibrillation spontaneously reverted to sinus rhythm during follow-up. One subject experienced a small myocardial infarction from an unrecognized small branch coronary occlusion. Another, experiencing cardiogenic shock at baseline, died of intractable heart failure after 6 weeks.

CONCLUSIONS

In this first human test, mitral loop cerclage annuloplasty was successful in 4 of 5 attempts, caused reverse remodeling (reduction in secondary mitral regurgitation and heart chamber volumes), and suggested electrical remodeling (reversion of atrial fibrillation). Further evaluation is warranted.

Anatomic relationship between left coronary artery and left atrium in patients undergoing atrial fibrillation ablation

BACKGROUND

Atrial fibrillation transcatheter ablation (TCA) is, within available atrial fibrillation rhythm control strategies, one of the most effective. To potentially improve ablation outcome in case of recurrent atrial fibrillation after a first procedure or in presence of structural myocardial disease, isolation of the pulmonary veins may be associated with extensive lesions within the left atrium. To avoid rare, but potentially life-threatening, complications, thorough knowledge and assessment of left atrium anatomy and its relation to structures in close proximity are, therefore, mandatory. Aim of the present study is to describe, by cardiac computed tomography, the anatomic relationship between aortic root, left coronary artery and left atrium in patients undergoing atrial fibrillation TCA.

METHODS AND RESULTS

The cardiac computed tomography scan of 21 patients affected by atrial fibrillation was elaborated to segment left atrium, aortic root and left coronary artery from the surrounding structures and the following distances measured: left atrium and aortic root; left atrium roof and aortic root; left main coronary artery and left atrium; circumflex artery and left atrium appendage; and circumflex artery and mitral valve annulus. Above all, the median distance between left atrium and aortic root (1.9, 1.5-2.1 mm), and between circumflex artery and left atrium appendage ostium (3.0, 2.1-3.4 mm) were minimal (≤3 mm). None of measured distances significantly varied between patients presenting paroxysmal versus persistent atrial fibrillation.

CONCLUSION

The anatomic relationship between left atrium and coronary arteries is extremely relevant when performing atrial fibrillation TCA by extensive lesions. Therefore, at least in the latter case, preablation imaging should be recommended to avoid rare, but potentially life-threatening, complications with the aim of an as well tolerated as possible procedure.

Trans-catheter mitral valve implantation for mitral regurgitation: clinical case description and literature review

Trans-catheter mitral valve implantation (TMVI) is actually the most attractive technique for treating patients with severe mitral regurgitation, who are denied surgical therapy. Recently, trans-catheter implantation of aortic biological prosthesis in mitral position has been done in compassionate cases, and very few experiences of TMVI in native non-calcified valves have been recently reported in very-high-risk patients, mainly with functional mitral regurgitation.Here, we report our case of TMVI using the second-generation CardiAQ prostheisis (CardiAQ Valve Technologies, Irvine, California, USA), reviewing the current state of the art.

Relationship of mitral valve annulus plane and circumflex-right coronary artery plane: Implications for Transcatheter Mitral Valve Implantation

AIM

Transcatheter mitral valve implantation (TMVI) is a novel technology for patients with severe mitral valve disease but at high surgical risk. Imaging guidance during the procedure is critical for successful device deployment. Identification of the mitral annular plane (MAP) with fluoroscopy during the procedure is limited by lack of clearly defined landmarks. We hypothesized that a plane defined by left circumflex-right coronary arteries (LCX-RCA) would have a consistent relationship to MAP.

METHODS AND RESULTS

We studied 25 patients with gated cardiac computed tomography. We identified the MAP and the LCX-RCA plane in mid systole and diastole. The distance between the two planes in prespecified four points (anterior, posterior, medial, and lateral) in the apical 2 and 3-chamber views. Alignment of the planes was described by cranial/caudal angulation for both planes in RAO 30° and LAO 90° (lateral) angulation. Mean age was 81 ± 9 years, 56% of patients had ≥2+ mitral regurgitation. In mid systole, the distances between the LCX-RCA plane and the MAP in the four points were < 5 mm in 92% of patients. In mid diastole, distances were < 5 mm in 100% of patients. In mid systole, the correlation between the caudal/cranial orientations of the 2 planes was 0.85 and 0.80 in the LAO 90° and RAO 30°, respectively (P = <0.001). In mid diastole, this was 0.92 and 0.92 in the LAO 90° and RAO 30°, respectively (P = <0.001).

CONCLUSION

LCX-RCA plane has a close and consistent relationship to the MAP and can be useful to guide TMVI. Accurate imaging of mitral valve annular plane during TMVI procedure is challenging. MAP guided by fluoroscopy might be crucial to guide successful prosthesis deployment. A plane defined by the left circumflex- right coronary arteries in the atrioventricular grove has a consistent relationship with MAP; this can be used aided by pre-procedural MDCT to guide TMVI procedure. © 2016 Wiley Periodicals, Inc.

Peri-procedural imaging for transcatheter mitral valve replacement

Mitral regurgitation (MR) has a high prevalence in older patient populations of industrialized nations. Common etiologies are structural, degenerative MR and functional MR secondary to myocardial remodeling. Because of co-morbidities and associated high surgical risk, open surgical mitral repair/replacement is deferred in a significant percentage of patients. For these patients transcatheter repair/replacement are emerging as treatment options. Because of the lack of direct visualization, pre- and intra-procedural imaging is critical for these procedures. In this review, we summarize mitral valve anatomy, trans-catheter mitral valve replacement (TMVR) options, and imaging in the context of TMVR.

Anomalous Origin of the Circumflex Artery: An Underestimated Threat During Mitral Valve Operation

Ischemic iatrogenic lesions can complicate surgical procedures on the mitral valve. One of the causative mechanisms is direct injury to or distortion of the circumflex coronary artery. The risk of damaging the circumflex coronary artery depends mainly on the proximity of that vessel to the posterior segment of the mitral annulus, and this varies from patient to patient. Herein, we report the case of an iatrogenic circumflex coronary artery lesion after mitral annuloplasty in a patient with an anomalous origin of the circumflex artery.

Mitral valve repair over five decades

It has become evident that mitral valve (MV) repair is the preferable treatment for the majority of patients presenting with severe mitral regurgitation (MR). This success clearly testifies that the surgical procedure is accessible, reproducible and is carrying excellent long-lasting results. From the pre-extracorporeal circulation's era to the last percutaneous approaches, a large variety of techniques have been proposed to address the different features of MV diseases. This article aimed at reviewing chronologically the development of these dedicated techniques through their origins and the debates that they generated in the literature.

[Mitral valve interventions: Where do we stand?]

Mitral valve regurgitation (MR) with resulting heart failure is one of the most prevalent types of valvular heart disease. Currently, various approaches to catheter-based therapy of MR are already available for patients deemed to be at high-risk for surgery. Most experience has been gained with the MitraClip® system. Technological developments in the field of catheter-based treatment of MR is advancing at a rapid pace, with treatment modalities suited for patients with both primary and secondary MR. Annuloplasty is the surgical gold standard, particularly for patients with secondary MR. For catheter-based therapy of secondary MR a distinction is made between indirect and direct annuloplasty, with the latter most closely corresponding to surgical ring implantation. Catheter-based mitral valve replacement is technically feasible at present; however, experience is still limited and only few reports have been published. Technological development is markedly slower than in the field of transcatheter aortic valve replacement, predominantly owing to the far more complex structure of the mitral valve. Positive experience has already been gained with catheter-based implantation of prostheses designed for the aortic valve into degenerated mitral valve bioprostheses and failed surgical mitral annuloplasty rings (valve-in-valve and valve-in-ring implantation). Further approaches to catheter-based treatment of MR in high-risk surgical patients are expected in the future.

Mitral valve anatomy: implications for transcatheter mitral valve interventions

Mitral regurgitation is a common valvular heart disease and its prevalence is expected to increase with population ageing. Percutaneous techniques for the treatment of mitral regurgitation are emerging as an alternative therapeutic option. However, the mitral valve is a complex structure, and a comprehensive understanding of the anatomy of the mitral valve apparatus and its surrounding structures is crucial for a correct selection of patients and the success of transcatheter mitral valve interventions.

Transcatheter mitral valve implantation via transapical approach: an early experience

OBJECTIVES

As many as 50% of patients with severe symptomatic mitral valve regurgitation are denied surgical valve replacement or repair due to high operative risk. We describe an early series of cases of transcatheter implantation with a CardiAQ™ mitral valve via a transapical approach.

METHODS

Three consecutive patients with an Society of Thoracic Surgeons (STS) mortality score of >22% were selected for transcatheter mitral valve implantation (TMVI) on compassionate grounds. All patients were elderly, had severe mitral regurgitation (MR), were in Class IV heart failure and deemed unsuitable for the MitraClip. Two of the patients had functional MR in the setting of ischaemic cardiomyopathy with left ventricular ejection fraction (LVEF) <40%, deemed while the remaining patient had chordal rupture with extensive anterior leaflet flail (preserved LVEF). Comorbidities included previous coronary artery bypass surgery (n = 2), severe pulmonary hypertension (n = 1) and moderate to severe chronic renal failure (n = 3). A CardiAQ mitral valve was implanted using fluoroscopy and transoesophageal (TEE) guidance via a standard transapical approach.

RESULTS

Accurate prosthesis positioning and deployment with immediate elimination of the MR was achieved in all 3 cases. Two patients made full clinical recovery and were discharged home. Post-procedural TEE performed on Days 1, 30 and 60 days showed good valve function, stable valve position and minimal LVOT gradient. One patient expired on the postoperative day 9 due to pneumonia.

CONCLUSIONS

TMVI using the CardiAQ™ device via a transapical approach is feasible and effective.

Advances in percutaneous treatment of mitral regurgitation

Percutaneous techniques for the treatment of mitral regurgitation have aroused much interest in recent years. Percutaneous mitral annuloplasty can be performed indirectly by using devices implanted in the coronary sinus or directly by using a retrograde approach. However, as yet, the results of these techniques are scarce and some devices have a high complications rate. The most frequent percutaneous mitral valve repair technique consists of mitral leaflet plication by implanting 1 or more percutaneous clips (MitraClip) in an imitation of the Alfieri surgical technique. Clinical experience with this device is broader than that with any other. The MitraClip device is associated with improved mitral regurgitation in a high percentage of carefully-selected patients. However, the single randomized study performed to date (EVEREST) showed its efficacy to be less than that of surgical repair and we await the results of new randomized studies that should clarify which patient-type can benefit most from this technique. Other left ventricular remodeling devices, tendinous cord implantation, and leaflet ablation are currently undergoing preclinical development or first-in-human experimentation. Finally, the development of biological prostheses for percutaneous mitral valve replacement is at an early stage. Many promising experiments at the preclinical phase and initial experiments in humans will very probably multiply in the near future. However, the true role of this technique in treating mitral valve disease will have to be evaluated in appropriately designed randomized controlled studies.

Devices for mitral valve repair

The natural history of severe mitral regurgitation (MR) is unfavorable, leading to left ventricular failure, atrial fibrillation, stroke, and death. Many patients affected by severe regurgitation (MR) do not currently undergo surgery, mainly due to the perceived risk of the procedure (old age, impaired left ventricular function, and comorbidities). Mitral transcatheter interventions carry the hope of minimizing risks while preserving clinical efficacy of surgical repair, as an alternative to conventional treatment. Multiple technologies and diversified approaches are under development with the purpose of treating MR in less invasive ways. They can be categorized based on the anatomical and patho-physiological addressed target. Among them, MitraClip (Abbott Vascular, Inc., Menlo Park, California) has emerged as a clinically safe and effective method for percutaneous mitral valve repair in patients either with degenerative and functional regurgitation. This device mimics the surgical edge-to-edge repair initially described by Alfieri in the early 1990s. Other repair technologies include percutaneous direct and indirect annuloplasty, neochordae implantation, and left ventricular reshaping. They are still in early phase clinical trials or preclinical studies. The combination of different repair techniques is likely to be required to achieve good long-lasting results. In the future, novel devices, improved knowledge, more efficient imaging, and transcatheter mitral prosthetic valve implantation may expand the indications to those patients currently not treated, as well as improve the results both in terms of early efficacy and long-term durability. These treatments are currently reserved to high-risk and inoperable patients, and their application requires an integrated Heart-Team approach. They represent the natural evolution of surgery and promise to expand treatment options and improve patients' outcomes in the near future.