Clinical outcomes and predictors of transapical transcatheter mitral valve replacement: the Tendyne Expanded Clinical Study.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) is a therapeutic option for patients with severe mitral regurgitation (MR) who are ineligible for conventional surgery. There are limited data on the outcomes of large patient cohorts treated with TMVR. AIMS: This study aimed to investigate the outcomes and predictors of mortality for patients treated with transapical TMVR. METHODS: This analysis represents the clinical experience of all patients enrolled in the Tendyne Expanded Clinical Study. Patients with symptomatic MR underwent transapical TMVR with the Tendyne system between November 2014 and June 2020. Outcomes and adverse events up to 2 years, as well as predictors of short-term mortality, were assessed. RESULTS: A total of 191 patients were treated (74.1±8.0 years, 62.8% male, Society of Thoracic Surgeons Predicted Risk of Mortality 7.7±6.6%). Technical success was achieved in 96.9% (185/191), and there were no intraprocedural deaths. At 30-day, 1- and 2-year follow-up, the rates of all-cause mortality were 7.9%, 30.8% and 40.5%, respectively. Complete MR elimination (MR <1+) was observed in 99.3%, 99.1% and 96.3% of patients, respectively. TMVR treatment resulted in consistent improvement of New York Heart Association Functional Class and quality of life up to 2 years (both p<0.001). Independent predictors of early mortality were age (odds ratio [OR] 1.11; p=0.003), pulmonary hypertension (OR 3.83; p=0.007), and institutional experience (OR 0.40; p=0.047). CONCLUSIONS: This study investigated clinical outcomes in the full cohort of patients included in the Tendyne Expanded Clinical Study. The Tendyne TMVR system successfully eliminated MR with no intraprocedural deaths, resulting in an improvement in symptoms and quality of life. Continued refinement of clinical and echocardiographic risks will be important to optimise longitudinal outcomes.

Outcomes After Transcatheter Mitral Valve Replacement According to Regurgitation Etiology.

BACKGROUND: Whether transcatheter mitral valve replacement (TMVR) devices perform similarly with respect to the underlying mitral regurgitation (MR) etiology remains unknown. The aim of the present analysis was to assess outcomes of TMVR according to the MR underlying etiology among the CHoice of OptImal transCatheter trEatment for Mitral Insufficiency (CHOICE-MI) registry. METHODS: Of 746 patients, 229 patients (30.7%) underwent TMVR. The study population was subdivided according to primary, secondary, or mixed MR. Patients with mitral annular calcification were excluded. The primary study endpoint was a composite endpoint of all-cause mortality or hospitalization for heart failure at 1 year. Secondary study endpoints were all-cause and cardiovascular mortality at 1 year, New York Heart Association functional class, and residual MR, both at discharge and 1 year. RESULTS: The predominant MR etiology was secondary MR (58.4%), followed by primary MR (28.7%) and mixed MR (12.9%). Technical success and procedural mortality were similar according to MR etiology. Discharge echocardiography revealed residual MR 2+ in 11.3%, 3.7%, and 5.3% of patients with primary, secondary, and mixed MR, respectively (P = .1). MR elimination was similar in all groups up to the 1-year follow-up. There was no difference in terms of primary combined outcome occurrence according to MR etiology. One-year all-cause mortality was reported in 28.8%, 24.2%, and 32.1% of patients with primary, secondary, and mixed MR, respectively (P = .07). CONCLUSIONS: In our study we did not find differences in short-term and 1-year outcomes after TMVR according to MR etiology.

Peri-procedural management of transcatheter mitral valve replacement in patients with heart failure.

Over the past decade, transcatheter mitral valve replacement (TMVR) technologies have evolved with the objective of improving outcomes for patients with severe mitral regurgitation (MR) deemed unsuitable for conventional mitral valve surgery. Although the safety and efficacy of transcatheter edge-to-edge mitral valve repair (TEER) is well-established, there is a sense amongst innovators that a major advantage of TMVR may be to offer a more complete solution for the correction of MR in patients whose complex anatomy means that the likelihood of achieving grade 0 or 1 MR with TEER is low. However, abrupt correction of MR in a poorly prepared left ventricle poses a number of unique haemodynamic challenges, particularly when sudden elimination of regurgitant flow causes a relative increase in left ventricular (LV) afterload. Rapid reduction in LV cavity size following MR elimination may itself result in relative LV outflow tract obstruction (LVOTO), irrespective of the intrinsic risk of LVOTO associated with TMVR. Nevertheless, TMVR on a beating heart affords the opportunity to study real-time invasive cardiac indices in high-risk patients with acute reversal of severe MR.

Characteristics and outcomes of patients screened for transcatheter mitral valve implantation: 1-year results from the CHOICE-MI registry.

AIMS: Transcatheter mitral valve implantation (TMVI) represents a novel treatment option for patients with mitral regurgitation (MR) unsuitable for established therapies. The CHOICE-MI registry aimed to investigate outcomes of patients undergoing screening for TMVI. METHODS AND RESULTS: From May 2014 to March 2021, patients with MR considered suboptimal candidates for transcatheter edge-to-edge repair (TEER) and at high risk for mitral valve surgery underwent TMVI screening at 26 centres. Characteristics and outcomes were investigated for patients undergoing TMVI and for TMVI-ineligible patients referred to bailout-TEER, high-risk surgery or medical therapy (MT). The primary composite endpoint was all-cause mortality or heart failure hospitalization after 1 year. Among 746 patients included (78.5 years, interquartile range [IQR] 72.0-83.0, EuroSCORE II 4.7% [IQR 2.7-9.7]), 229 patients (30.7%) underwent TMVI with 10 different dedicated devices. At 1 year, residual MR ≤1+ was present in 95.2% and the primary endpoint occurred in 39.2% of patients treated with TMVI. In TMVI-ineligible patients (n = 517, 69.3%), rates of residual MR ≤1+ were 37.2%, 100.0% and 2.4% after bailout-TEER, high-risk surgery and MT, respectively. The primary endpoint at 1 year occurred in 28.8% of patients referred to bailout-TEER, in 42.9% of patients undergoing high-risk surgery and in 47.9% of patients remaining on MT. CONCLUSION: This registry included the largest number of patients treated with TMVI to date. TMVI with 10 dedicated devices resulted in predictable MR elimination and sustained functional improvement at 1 year. In TMVI-ineligible patients, bailout-TEER and high-risk surgery represented reasonable alternatives, while MT was associated with poor clinical and functional outcomes.

2-Year Outcomes of Transcatheter Mitral Valve Replacement in Patients With Severe Symptomatic Mitral Regurgitation.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) is feasible for selected patients with severe mitral regurgitation (MR) who are poor candidates for valve surgery. Intermediate-term to long-term TMVR outcomes have not been reported. OBJECTIVES: This study sought to evaluate the safety and effectiveness through 2-year follow-up of TMVR in high-surgical-risk patients with severe MR. METHODS: The first 100 patients enrolled in the Expanded Clinical Study of the Tendyne Mitral Valve System, an open-label, nonrandomized, prospective study of transapical TMVR, were followed for 2 years. RESULTS: The patients (aged 74.7 ± 8.0 years, 69.0% male) had symptomatic (66.0% New York Heart Association [NYHA] functional class III or IV) grade 3+ or 4+ MR that was secondary or mixed in 89 (89.0%). Prostheses were successfully implanted in 97 (97.0%) patients. At 2 years, all-cause mortality was 39.0%; 17 (43.6%) of 39 deaths occurred during the first 90 days. Heart failure hospitalization (HFH) fell from 1.30 events per year preprocedure to 0.51 per year in the 2 years post-TMVR (P < 0.0001). At 2 years, 93.2% of surviving patients had no MR. No patient had >1+ MR. The improvement in symptoms at 1 year (88.5% NYHA functional class I or II) was sustained to 2 years (81.6% NYHA functional class I or II). Among survivors, the left ventricular ejection fraction was 45.6 ± 9.4% at baseline and 39.8 ± 9.5% at 2 years (P = 0.0012). Estimated right ventricular systolic pressure decreased from 47.6 ± 8.6 mm Hg to 32.5 ± 10.4 mm Hg (P < 0.005). CONCLUSIONS: In this study, the impact of TMVR on severity of MR, reduction in HFH rate, and improvement in symptoms was sustained through 2 years. All-cause mortality and the need for HFH was highest in the first 3 months postprocedure. (Expanded Clinical Study of the Tendyne Mitral Valve System; NCT02321514).

Improved right ventricular function following transapical transcatheter mitral valve implantation for severe mitral regurgitation.

BACKGROUND: Transapical transcatheter mitral valve implantation (TMVI) may be a therapeutic option for patients with severe mitral regurgitation (MR) excluded from cardiac surgery due to excessive risk. Exclusion criteria frequently include pulmonary hypertension and right ventricular (RV) dysfunction. The effect of TMVI on RV function has not previously been well-characterized. The aim of this study was to examine the procedural and 3-month impact of TMVI on RV hemodynamics and function. METHODS: This was a multi-center, retrospective, observational cohort study of patients with >3+MR undergoing TMVI. Pre- and post-TMVI hemodynamics were assessed with right heart catheterization. RV function was assessed at baseline, pre-discharge and at 3-months by echocardiography. RESULTS: Forty-six patients (age 72±9 years; 34 men) with ≥3+MR underwent TMVI over a 5-year period. Successful device implantation was achieved in all patients with abolition of MR (p < 0.001) and reduction in left-ventricular end-diastolic volume (p = 0.001). RV stroke work index (RVSWI) increased intra-operatively (7 ± 4 g/m/beat/m2 vs 11 ± 5 g/m/beat/m2; p < 0.001). At 3-months there were reductions in severity of tricuspid regurgitation (TR) (p < 0.001) and pulmonary artery systolic pressure (PASP) (49 ± 16 mmHg vs 36 ± 12 mmHg; p < 0.001), and improvements in RV fractional area change (28 ± 7% vs 34 ± 9%, p<0.001), tricuspid annular plane systolic excursion (TAPSE) (1.0 ± 0.3 vs 1.5 ± 0.5cm, p = 0.03), and RV free wall longitudinal strain (-14.2±5.0 vs -17.6±7.3, p = 0.05). CONCLUSIONS: Transapical TMVI results in significant improvement of RV function that is sustained to 3-months as evidenced by improvements in RVSWI and RV fractional area change, as well as reductions in PASP and TR severity.

Spontaneous Coronary Artery Dissection and Fibromuscular Dysplasia: Vasculopathies With a Predilection for Women.

The burden of cardiovascular disease in women is being increasingly appreciated. Nevertheless, both clinicians and the general public are largely unaware that cardiovascular disease is the leading cause of death worldwide in women in all countries and that outcomes after a heart attack are worse for women than men. Of note, certain types of cardiovascular disease have a predilection for women, including spontaneous coronary artery dissection (SCAD) and fibromuscular dysplasia (FMD). Although uncommon, SCAD is being increasingly recognised as the cause of an acute coronary syndrome (ACS) and can recur. It is a potentially fatal, under-diagnosed condition that affects relatively young women, who often have few traditional risk factors, and is the commonest cause of a myocardial infarction associated with pregnancy. In contrast, FMD often remains silent but when manifested can also cause major sequelae, including renal infarction, stroke, cervical artery dissection and gut infarction. Here we provide an update on the diagnosis, aetiology and management of these important disorders that overwhelmingly affect women.

Spontaneous Coronary Artery Dissection: Insights on Rare Genetic Variation From Genome Sequencing.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) occurs when an epicardial coronary artery is narrowed or occluded by an intramural hematoma. SCAD mainly affects women and is associated with pregnancy and systemic arteriopathies, particularly fibromuscular dysplasia. Variants in several genes, such as those causing connective tissue disorders, have been implicated; however, the genetic architecture is poorly understood. Here, we aim to better understand the diagnostic yield of rare variant genetic testing among a cohort of SCAD survivors and to identify genes or gene sets that have a significant enrichment of rare variants. METHODS: We sequenced a cohort of 384 SCAD survivors from the United Kingdom, alongside 13 722 UK Biobank controls and a validation cohort of 92 SCAD survivors. We performed a research diagnostic screen for pathogenic variants and exome-wide and gene-set rare variant collapsing analyses. RESULTS: The majority of patients within both cohorts are female, 29% of the study cohort and 14% validation cohort have a remote arteriopathy. Four cases across the 2 cohorts had a diagnosed connective tissue disorder. We identified pathogenic or likely pathogenic variants in 7 genes (PKD1, COL3A1, SMAD3, TGFB2, LOX, MYLK, and YY1AP1) in 14/384 cases in the study cohort and in 1/92 cases in the validation cohort. In our rare variant collapsing analysis, PKD1 was the highest-ranked gene, and several functionally plausible genes were enriched for rare variants, although no gene achieved study-wide statistical significance. Gene-set enrichment analysis suggested a role for additional genes involved in renal function. CONCLUSIONS: By studying the largest sequenced cohort of SCAD survivors, we demonstrate that, based on current knowledge, only a small proportion have a pathogenic variant that could explain their disease. Our findings strengthen the overlap between SCAD and renal and connective tissue disorders, and we highlight several new genes for future validation.

Successful repositioning of apically tethered transcatheter mitral valve replacement in the off-bypass, beating heart.

A 73-year-old man with severe, symptomatic secondary mitral regurgitation (MR) underwent successful transcatheter mitral valve replacement using the Tendyne™ mitral valve system. The device was deployed from the left ventricular (LV) apex and secured in position by a tether attached to an epicardial pad. Three days postoperatively, the patient developed hemolytic anemia and a paravalvular leak (PVL) associated with indentation of the LV apex. Adjustment of the tether tension and placement of an epicardial disc under the pad resulted in reduction in the PVL, and resolution of the hemolytic anemia.

Takotsubo cardiomyopathy following unintentionally large subcutaneous adrenaline injection: a case report.

INTRODUCTION: Stress cardiomyopathy, also known as takotsubo syndrome, is characterized by transient left ventricular dysfunction not attributable to obstructive epicardial coronary artery disease. Several pathological mechanisms have been proposed, including multivessel coronary artery vasospasm, coronary microcirculatory dysfunction, and excess catecholamine secretion. CASE PRESENTATION: A 68-year-old male presented to our institution for elective surgical removal of a cutaneous basal cell carcinoma on the right side of his face. Within minutes following the administration of local anaesthesia, the patient developed severe hypertension, tachycardia, ST-segment elevation on the electrocardiogram, and non-sustained broad-complex tachycardia. Urgent cardiac catheterization revealed non-obstructive coronary artery disease and left ventriculography demonstrated apical hypokinesia and moderate systolic dysfunction consistent with the takotsubo syndrome. On review of the medications administered, it was noted that an unintentionally large dose of adrenaline (4mg) had been injected subcutaneously with lignocaine. He was monitored in the coronary care and recovered fully with supportive care only. Bisoprolol was initiated on day 1 post procedure. On follow-up one month later, his left ventricular function had normalized. DISCUSSION: Our case report provides direct evidence supporting the pathogenetic role of excess catecholamine secretion in the development of the takotsubo syndrome. A review of the literature reveals that both exogenous catecholamine administration (adrenaline injection in the context of anaphylaxis or infiltrative anaesthesia) and excess endogenous catecholamine (phaechromocytoma) secretion has been associated with the takotsubo syndrome. Local infiltrative anaesthesia with the addition of adrenaline is commonly used as a vasoconstrictor in a wide variety of surgical procedures. To reduce the risk of adverse events, the lowest effective concentration of adrenaline to provide pain control and vasoconstriction is recommended.

Transcatheter Mitral Valve Replacement for Patients With Symptomatic Mitral Regurgitation: A Global Feasibility Trial.

BACKGROUND: Symptomatic mitral regurgitation (MR) is associated with high morbidity and mortality that can be ameliorated by surgical valve repair or replacement. Despite this, many patients with MR do not undergo surgery. Transcatheter mitral valve replacement (TMVR) may be an option for selected patients with severe MR. OBJECTIVES: This study aimed to examine the effectiveness and safety of TMVR in a cohort of patients with native valve MR who were at high risk for cardiac surgery. METHODS: Patients underwent transcatheter, transapical delivery of a self-expanding mitral valve prosthesis and were examined in a prospective registry for short-term and 30-day outcomes. RESULTS: Thirty patients (age 75.6 ± 9.2 years; 25 men) with grade 3 or 4 MR underwent TMVR. The MR etiology was secondary (n = 23), primary (n = 3), or mixed pathology (n = 4). The Society of Thoracic Surgeons Predicted Risk of Mortality was 7.3 ± 5.7%. Successful device implantation was achieved in 28 patients (93.3%). There were no acute deaths, strokes, or myocardial infarctions. One patient died 13 days after TMVR from hospital-acquired pneumonia. Prosthetic leaflet thrombosis was detected in 1 patient at follow-up and resolved after increased oral anticoagulation with warfarin. At 30 days, transthoracic echocardiography showed mild (1+) central MR in 1 patient, and no residual MR in the remaining 26 patients with valves in situ. The left ventricular end-diastolic volume index decreased (90.1 ± 28.2 ml/m2 at baseline vs. 72.1 ± 19.3 ml/m2 at follow-up; p = 0.0012), as did the left ventricular end-systolic volume index (48.4 ± 19.7 ml/m2 vs. 43.1 ± 16.2 ml/m2; p = 0.18). Seventy-five percent of the patients reported mild or no symptoms at follow-up (New York Heart Association functional class I or II). Successful device implantation free of cardiovascular mortality, stroke, and device malfunction at 30 days was 86.6%. CONCLUSIONS: TMVR is an effective and safe therapy for selected patients with symptomatic native MR. Further evaluation of TMVR using prostheses specifically designed for the mitral valve is warranted. This intervention may help address an unmet need in patients at high risk for surgery. (Early Feasibility Study of the Tendyne Mitral Valve System [Global Feasibility Study]; NCT02321514).

Outcomes of patients with spontaneous coronary artery dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is an uncommon but serious condition presenting as an acute coronary syndrome (ACS) or cardiac arrest. The pathophysiology and outcomes are poorly understood. We investigated the characteristics and outcomes of patients presenting with SCAD. METHODS: In a retrospective study of a large cohort of patients with SCAD, data were collected regarding clinical presentation, patient characteristics, vascular screening, coronary artery involvement and clinical outcomes. RESULTS: 40 patients with SCAD (95% women, mean age 45±10 years) were included. At least 1 traditional cardiovascular risk factor was present in 40% of patients. Migraine was reported in 43% of patients. Events preceding SCAD included parturition (8%), physical stress (13%), emotional stress (10%) and vasoconstrictor substance-use (8%). 65% of patients had a non-ST elevation ACS (NSTEACS) at presentation, 30% had an ST elevation myocardial infarction (STEMI) and 13% had a cardiac arrest. The left anterior descending artery was most frequently involved (68% of patients), and 13% had involvement of multiple coronary territories. Fibromuscular dysplasia (FMD) was identified in 7 (37%) of 19 patients screened. 68% of patients were managed medically, 30% had percutaneous coronary intervention and 5% had coronary artery bypass grafting. Over a median 16-month follow-up period, 8% of patients had at least 1 recurrent SCAD event. There were no deaths. CONCLUSIONS: Patients with SCAD in this study often had multiple coronary territories involved (13%) and extracardiac vascular abnormalities, suggesting a systemic vascular process, which may explain the high incidence of migraine. All patients with SCAD should be screened for FMD and followed closely due to the possibility of recurrence.

Effects of antiplatelet therapy on platelet extracellular vesicle release and procoagulant activity in health and in cardiovascular disease.

Dual antiplatelet therapy with aspirin and clopidogrel is commonly used to prevent recurrent ischemic events in patients with cardiovascular disease. Whilst their effects on platelet reactivity are well documented, it is unclear, however, whether antiplatelet therapy inhibits platelet extracellular vesicle (EV) release. The aim of this study was to investigate the effects of antiplatelet therapy on platelet EV formation and procoagulant activity. Blood samples from 10 healthy controls not receiving antiplatelet therapy were incubated in vitro with aspirin or a P2Y12 inhibitor (MeSAMP). Blood samples from 50 patients receiving long-term dual antiplatelet therapy and undergoing coronary angiography were also studied. Platelet reactivity was assessed by Multiplate™ impedance aggregometry. Platelet EV formation and procoagulant activity of pretreated and untreated blood samples in response to arachidonic acid (AA), adenosine diphosphate (ADP), ADP+PGE1, and thrombin receptor-activating peptide (TRAP) stimulation were assessed by flow cytometry and Procoag-PL assays, respectively. Incubation of normal platelets with aspirin significantly inhibited AA-induced platelet reactivity, EV formation, and procoagulant activity, whilst MeSAMP significantly inhibited platelet reactivity and EV formation in response to AA, ADP, and TRAP, but had minimal effect on procoagulant activity. Most patients receiving dual antiplatelet therapy showed an appropriate reduction in platelet reactivity in response to their treatment; however there was not complete inhibition of increased platelet and EV procoagulant activity in response to ADP, AA, or TRAP. In addition, we could not find any correlation between platelet reactivity and procoagulant activity in patients receiving dual antiplatelet therapy.

Percutaneous treatment of chronic thromboembolic pulmonary hypertension (CTEPH).

Chronic thromboembolic pulmonary hypertension (CTEPH) occurs as a consequence of a series of events that includes arterial obstruction by embolic material, secondary in situ thrombosis, cytokine activation and inflammation, and small vessel angiopathy. Medical therapies have a limited efficacy. Only the guanylate cyclase stimulator, riociguat, is approved for this condition. Surgical pulmonary endarterectomy is the definitive treatment for patients with proximal disease, but one third of patients with CTEPH are considered ineligible for surgery. Another third have significant residual pulmonary hypertension postoperatively. Balloon pulmonary angioplasty is an option for these patients. The procedure has a low procedural mortality and high efficacy in experienced centres but has not yet been subjected to rigorous evaluation in clinical trials. Alternative options for percutaneous management include atrial septostomy and pulmonary artery denervation. Experience with these procedures is accumulating, but adequately powered, controlled trials have not yet been performed.

Impact of New-generation Hybrid Imaging Technology on Radiation Dose during Percutaneous Coronary Interventions and Trans-femoral Aortic Valve Implantations: A comparison with conventional flat-plate angiography.

BACKGROUND: Technological advancements in newer-generation catheterisation laboratories may reduce patient and occupational radiation exposure. METHODS: We compared fluoroscopy time and dose-area product (DAP) between a Philips Allura X-PER FD20 and Siemens Artis Zeego Hybrid systems for 47 single-vessel percutaneous coronary interventions (PCI) and 35 transcatheter aortic valve implantations (21 Corevalve, 14 Edwards Sapien TAVI) using the FD20, versus 30 PCI and 28 TAVI (15 Corevalve, 13 Sapien) with the Zeego over a 24-month period. RESULTS: Multivariate analysis revealed that, adjusting for patient weight and fluoroscopy time, DAP (median, interquartile range) was 26% lower for PCI with the Zeego than the FD20 [55.6 (27.0-91.5) vs 77.6 (51.2-129.1) Gy.cm(2), P=0.03)] and using tomographic imaging with the Zeego did not increase DAP for TAVI procedures [98.1 (65.9-136.6) vs 112.4 (64.9-156.2) Gy.cm(2) (P=NS). Although fluoroscopy times were longer for TAVI procedures than PCI with both systems (23.5-24.4 vs 7.3-9.2mins, p<0.0001), there was a significant difference in DAP between PCI and combined TAVI with the Zeego (55.6 vs 112.4Gy.cm(2), P<0.006) but not with the FD20 (77.6 vs 98.1Gy.cm(2), P=NS). CONCLUSION: Specific dose-reducing features of the new-generation system reduced DAP more for PCI than TAVI, as valve replacement procedures use additional cine-acquisition not necessary for PCI.

Late surgical explantation and aortic valve replacement after transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) in patients with bicuspid aortic valve disease is associated with higher rates of paravalvular aortic regurgitation, which may require subsequent surgical correction. We report a case of successful late surgical CoreValve explantation 1,389 days after TAVI in a patient with bicuspid aortic valve stenosis and McArdle's disease who developed severe paravalvular aortic regurgitation. We confirm that neoendothelialization and incorporation of the nitinol cage into the aortic wall had occurred at nearly 4 years postimplantation, although explantation with careful endarterectomy could still be performed without requiring simultaneous aortic root replacement.

The MitraClip experience and future percutaneous mitral valve therapies.

Mitral regurgitation is the most common valve abnormality worldwide and its prevalence is expected to increase in the future due to aging of the population. Percutaneous mitral valve repair therapies may offer an opportunity to treat severe MR in the elderly or other high-risk groups who would otherwise be ineligible for surgery. The MitraClip system uses edge-to-edge coaptation of the mitral leaflets to create a double-orifice valve and reduce MR. It has been performed in over 10 000 patients to date, and as experience has improved, procedural times have shortened from over 200 minutes to less than 100 minutes, with increasing numbers of patients being left with ≤ grade 2+ MR. This review will focus on the literature available on MitraClip and other novel percutaneous techniques that are being developed for the treatment of severe MR.

Radiation dose during percutaneous treatment of structural heart disease.

BACKGROUND: With the increased application of structural heart intervention techniques, there is concern over increasing radiation dose, especially during lengthy procedures. METHODS: We compared data from 91 consecutive single-vessel percutaneous coronary interventions, 69 patent foramen ovale closures, 25 atrial septal defect closures, 49 percutaneous transluminal mitral valvuloplasties, 57 balloon aortic valvuloplasties, 53 trans-catheter aortic valve implantations (TAVI), 21 left atrial appendage occlusions and 7 MitraClip procedures. RESULTS: The following fluoroscopy times and dose-area product (median, interquartile range) were recorded: patent foramen ovale closure (7.8, 5.3-10.9 minutes; 16.9, 7.5-30.6 Gycm(2)), atrial septal defect closure (10.1, 7.3-13 minutes; 15.5, 11.6-30.5 Gycm(2)), percutaneous transluminal mitral valvuloplasty (14.3, 11.4-24.2 minutes; 37.4, 19.8-87.0 Gycm(2)), balloon aortic valvuloplasty (8.4, 5.2-13.2 minutes; 19.8, 10.2-30.0 Gycm(2)), Edwards Sapien TAVI (24.0, 19.3-34.4 minutes; 86.4, 64.0-111.4 Gycm(2)), Medtronic CoreValve TAVI (19.4, 15.0-26.0 minutes; 101.9, 52.6-143.2 Gycm(2)), left atrial appendage occlusion (18.5, 15.7-29.1 minutes; 84.1, 36.4-140.0 Gycm(2)), Mitraclip procedures (37.2, 14.2-59.9 minutes; 89.1, 26.2-118.7 Gycm(2)), coronary angiography and single vessel percutaneous coronary intervention (6.6, 5.1-11.0 minutes; 62.5, 37.0-95.8 Gycm(2)). CONCLUSION: For structural heart interventions, dose-area product was not significantly greater than for coronary angiography with single-vessel percutaneous coronary artery intervention. This should be reassuring to patients and staff attending prolonged structural heart interventions.