Different Techniques of Surgical Left Atrial Appendage Closure and Their Efficacy: A Systematic Review.

Background: Atrial fibrillation has been identified as an independent risk factor for thromboembolic events. Since 1948 different surgical techniques have described the feasibility and the rationale of left atrial surgical appendage closure. The aim of this systematic review is to evaluate the reported patency rates of different surgical techniques. Methods: This systematic review was conducted according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Two independent investigators searched the PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, and OVID® (Wolters Kluwer, Alphen aan den Rijn, Netherlands) to identify relevant studies. Consecutively, a PICO (Population, Intervention, Comparison and Outcomes) strategy assessment of literature was performed to search eventual other relevant studies that may have been ignored. Results: A total of 42 studies were included in our analysis. The total number of patients who underwent surgical left atrial appendage closure was 5671, and in 61.2% an imaging follow up was performed, mostly with transesophageal echocardiographic evaluation. Success rate for the different techniques was: Clip deployment 98%; Lariat procedure 88%; Surgical amputation 91%; Endocardial suture 74.3%, Epicardial suture 65%; Left atrial appendage closure (LAAC) ligation 60.9%; Stapler technique with excision of left atrial appendage (LAA) 100%; Stapler without excision 70%. Conclusions: To date, data on surgical left atrial appendage closure are poor and not standardized, even if reported rates are acceptable and comparable to transcatheter procedures. If validated on large-scale non-retrospective and multicentric studies, these promising developments may offer a valuable alternative for patients with atrial fibrillation (AF) and ineligible for oral anticoagulation therapy.

Incidental pseudoaneurysm of the mitral-aortic intervalvular fibrosa in asymptomatic patient: A case report.

Pseudoaneurysm of the mitral-aortic intervalvular fibrosa (P-MAIVF) can be a rare but life-threatening complication of infective endocarditis, cardiac surgery, or blunt chest trauma. Congenital heart diseases especially in young patients are reported as additionally predisposing factors. We present the case of an asymptomatic 52 years-old male with bicuspid aortic valve and gastrointestinal polyposis syndrome in whom a P-MAIVF was incidentally detected. The patient successfully underwent pseudoaneurysm surgical repair and aortic valve replacement and despite no evident causes were found we hypothesized addiotional underlying mechanism of P-MAIVF.

Acute thrombotic occlusion of a brachiocephalic branch graft and pseudoaneurysm formation after debranching surgery for a "non-A non-B" aortic dissection.

Non-A non-B aortic dissection is a pathology with potentially life-threatening consequences, and aortic debranching followed by thoracic endovascular aortic repair is one of the possible treatment options. Branch graft occlusion is an infrequent complication and no definite guidelines exist about postoperative antithrombotic therapy nor preoperative evaluation of individual anatomical characteristics-in particular regarding cerebral circulation-in such patients. We present the case of a 54-year-old man undergoing an aortic debranching procedure for a thoracoabdominal aortic dissection originating in the aortic arch, complicated by thrombotic occlusion of the brachiocephalic branch of the prosthesis and pseudoaneurysm of the ascending aorta, with our management and considerations.

Observed versus predicted mortality after isolated tricuspid valve surgery.

BACKGROUND: Aim of this study is to analyse the performances of Clinical Risk Score (CRS) and European System for Cardiac Operative Risk Evaluation (EuroSCORE)-II in isolated tricuspid surgery. METHODS: Three hundred and eighty-three patients (54 ± 16 year; 54% female) were enrolled. Receiver operating characteristic analysis was performed to evaluate the relationship between the true positive fraction of test results and the false-positive fraction for a procedure. RESULTS: Considering the 30-day mortality the area under the curve was 0.6 (95% confidence interval [CI] 0.50-0.72) for EuroSCORE II and 0.7 (95% CI 0.56-0.84) for CRS-score. The ratio of expected/observed mortality showed underestimation when considering EuroSCORE-II (min. 0.46-max. 0.6). At multivariate analysis, the CRS score (p = .005) was predictor of late cardiac death. CONCLUSION: We suggest using both scores to obtain a range of expected mortality. CRS to speculate on late survival.

Circulating Levels of Ferritin, RDW, PTLs as Predictive Biomarkers of Postoperative Atrial Fibrillation Risk after Cardiac Surgery in Extracorporeal Circulation.

Postoperative atrial fibrillation (POAF) is the most common arrhythmia after cardiac surgery in conventional extracorporeal circulation (CECC), with an incidence of 15-50%. The POAF pathophysiology is not known, and no blood biomarkers exist. However, an association between increased ferritin levels and increased AF risk, has been demonstrated. Based on such evidence, here, we evaluated the effectiveness of ferritin and other haematological parameters as POAF risk biomarkers in patients subjected to cardiac surgery. We enrolled 105 patients (mean age = 70.1 ± 7.1 years; 70 men and 35 females) with diverse heart pathologies and who were subjected to cardiothoracic surgery. Their blood samples were collected and used to determine hematological parameters. Electrocardiographic and echocardiographic parameters were also evaluated. The data obtained demonstrated significantly higher levels of serum ferritin, red cell distribution width (RDW), and platelets (PLTs) in POAF patients. However, the serum ferritin resulted to be the independent factor associated with the onset POAF risk. Thus, we detected the ferritin cut-off value, which, when ≥148.5 ng/mL, identifies the subjects at the highest POAF risk, and with abnormal ECG atrial parameters, such as PW indices, and altered structural heart disease variables. Serum ferritin, RDW, and PTLs represent predictive biomarkers of POAF after cardiothoracic surgery in CECC; particularly, serum ferritin combined with anormal PW indices and structural heart disease variables can represent an optimal tool for predicting not only POAF, but also the eventual stroke onset.

Echocardiography and Correction of Mitral Regurgitation: An Unbreakable Link.

BACKGROUND: Degenerative mitral valve (MV) disease causing mitral regurgitation (MR) is the most common organic valve pathology and is classified based on leaflet motion. MV repair is indicated as the preferred technique (Class I indication) when the results are expected to be durable. Therefore, a detailed and systematic evaluation of MV apparatus is pivotal in allowing the proper surgical planning, as well as the screening for trans catheter-based treatment when surgery is not indicated. AIM: The aim of the present review is to describe the crucial role of both Transthoracic Echocardiography (TTE) and Transesophageal Echocardiography (TEE) in the decisional process and the guidance of MV repair procedures. TTE is the main investigation and the first approach used to make diagnosis of MR, to assess the severity and to describe the underlying mechanism, while TEE, especially with 3D echocardiography, has been shown to be useful for clarifying complicated valvular anatomy, assessing the surgical result and detecting complications. The surgical treatment of MR takes advantage of ultrasound evaluation of MV apparatus at any stage of the process, thus making the link between surgery and echocardiography unbreakable throughout the perioperative phase.

An overview of the molecular mechanisms underlying development and progression of bicuspid aortic valve disease.

Bicuspid aortic valve (BAV) is a common congenital heart malformation frequently associated with the development of aortic valve diseases and severe aortopathy, such as aortic dilatation, aneurysm and dissection. To date, different genetic loci have been identified in syndromic and non- syndromic forms of BAV. Among these, genes involved in the regulation of extracellular matrix remodelling, epithelial to mesenchymal transition and nitric oxide metabolism appear to be the main contributors to BAV pathogenesis. However, no- single gene model explains BAV inheritance, suggesting that more factors are simultaneously involved. In this regard, characteristic epigenetic and immunological profiles have been documented to contradistinguish BAV individuals. In this review, we provide a comprehensive overview addressing molecular mechanisms involved in BAV development and progression.

The Effect of Propofol and Dexmedetomidine Sedation on Norepinephrine Requirements in Septic Shock Patients: A Crossover Trial.

OBJECTIVES: Propofol-based sedation may increase hemodynamic instability by decreasing vascular tone and venous return. Incremental exogenous catecholamines doses may be required to counteract such effects, aggravating the deleterious effects of sympathetic overstimulation. α-2 adrenergic agonists have been reported to decrease norepinephrine requirements in experimental septic shock. The aim of the present study is to test the hypothesis that switching from sedation with propofol to the α-2 agonist dexmedetomidine may decrease norepinephrine doses in septic shock. DESIGN: Prospective open-label crossover study. SETTINGS: University hospital, ICU. PATIENTS: Thirty-eight septic shock patients requiring norepinephrine to maintain adequate mean arterial pressure and needing deep sedation with propofol and remifentanil to maintain a Richmond Agitation-Sedation Scale score between -3 and -4. INTERVENTIONS: An initial set of measurements including hemodynamics, norepinephrine doses, and depth of sedation were obtained during sedation with propofol. Propofol was then replaced by dexmedetomidine and a second set of data was obtained after 4 hours of dexmedetomidine infusion. Sedation was switched back to propofol, and a final set of measurements was obtained after 8 hours. A Richmond Agitation-Sedation Scale score between -3 and -4 was maintained during the study period. MEASUREMENTS AND MAIN RESULTS: Norepinephrine requirements decreased from 0.69 ± 0.72 µg/kg/min before dexmedetomidine to 0.30 ± 0.25 µg/kg/min 4 hours after dexmedetomidine infusion, increasing again to 0.42 ± 0.36 µg/kg/min while on propofol 8 hours after stopping dexmedetomidine (p < 0.005). Dexmedetomidine dosage was 0.7 ± 0.2 µg/kg/hr. Before and after dexmedetomidine infusion, sedative doses remained unchanged (propofol 2.6 ± 1.2 vs 2.6 ± 1.2 mg/kg/hr; p = 0.23 and remifentanil 1.27 ± 0.17 vs 1.27 ± 0.16 µg/kg/hr; p = 0.52, respectively). Richmond Agitation-Sedation Scale was -4 (-4 to -3) before, -4 (-4 to -3) during, and -4 (-4 to -4) after dexmedetomidine (p = 0.07). CONCLUSIONS: For a comparable level of sedation, switching from propofol to dexmedetomidine resulted in a reduction of catecholamine requirements in septic shock patients.

Cerebral Metastases in Patients with Left Atrial Myxoma.

We describe two cases of cardiac myxomas with cerebral metastases and review the literature on this subject. doi: 10.1111/jocs.12727 (J Card Surg 2016;31:289-293).

Total adiponectin is inversely associated with platelet activation and CHA2DS2-VASc score in anticoagulated patients with atrial fibrillation.

BACKGROUND: Adiponectin (APN) possesses anti-inflammatory and antiatherogenic effects. Atrial fibrillation (AF) is burdened by enhanced systemic inflammation and platelet activation, as documented by increased blood levels of soluble CD40L (sCD40L). The interplay between APN and platelet activation in AF is still undefined. MATERIALS AND METHODS: Circulating levels of APN and sCD40L were measured in 257 anticoagulated nonvalvular AF patients. Exclusion criteria were as follows: prosthetic heart valves, cardiac revascularization in the previous year, severe cognitive impairment, chronic infectious or autoimmune diseases, and active cancer. RESULTS: Mean age was 72.9 (±8.7) years and 41.6% were female. Serum APN and plasmatic sCD40L were inversely correlated (R -0.626, P < 0.001). A progressive increase of sCD40L across tertiles of CHA2DS2-VASc score was observed (rS 0.473, P < 0.001), whilst APN was inversely correlated (rS -0.463, P < 0.001). A multivariable linear regression analysis showed that CHA2DS2-VASc score (B -0.227, P < 0.001) and sCD40L (B -0.524, P < 0.001) correlated to APN. CONCLUSIONS: AF patients at high risk of stroke disclose low and high levels of APN and sCD40L, respectively, suggesting a role for APN if it favors platelet activation in vivo in this clinical setting. Enhancing APN levels may be a future goal to reduce the risk of vascular outcomes in AF patients.

Evolocumab Treatment in Dyslipidemic Patients Undergoing Coronary Artery Bypass Grafting: One-Year Safety and Efficacy Results.

Background: The inhibition of PCSK9 lowered LDL cholesterol levels, reducing the risk of cardiovascular events. However, the effect on patients who have undergone surgical myocardial revascularization has not yet been evaluated. Methods: From January 2017 to December 2022, 180 dyslipidemic patients who underwent coronary artery bypass were included in the study. Until December 2019, 100 patients optimized therapy with statin ± ezetimibe (SG). Since January 2020, 80 matched patients added treatment with Evolocumab every 2 weeks (EG). All 180 patients were followed-up at 3 and 12 months, comparing outcomes. Results: The two groups are homogenous. At 3 months and 1 year, a significant decrease in the parameter mean levels of LDL cholesterol and total cholesterol is detected in the Evolocumab group compared to the standard group. No mortality was detected in either group. No complications or drug discontinuation were recorded. In the SG group, five patients (5%) suffered a myocardial infarction during the 1-year follow-up. In the EG group, two patients (2.5%) underwent PTCA due to myocardial infarction. There is no significant difference in overall survival according to the new treatment (p-value = 0.9), and the hazard ratio is equal to 0.94 (95% C.I.: [0.16-5.43]; p-value = 0.9397). Conclusions: The use of Evolocumab, which was started immediately after coronary artery bypass graft surgery, significantly reduced LDL cholesterol and total cholesterol levels compared to statin treatment alone and is completely safe. However, at one year of follow-up, this result did not have impact on the reduction in major clinical events.

Prognostic role of endocarditis in isolated tricuspid valve surgery. A propensity-weighted study.

OBJECTIVES: The role of the underlying etiology in isolated tricuspid valve surgery has not been investigated extensively in current literature. Aim of this study was to analyse outcomes of patients undergoing surgery due to endocarditis compared to other pathologies. METHODS: The SURTRI study is a multicenter study enrolling adult patients who underwent isolated tricuspid valve surgery (n = 406, 55 ± 16 y.o.; 56% female) at 13 international sites. Propensity weighted analysis was performed to compare groups (IE group n = 107 vs Not-IE group n = 299). RESULTS: No difference was found regarding the 30-day mortality (Group IE: 2.8% vs Group Not-IE = 6.8%; OR = 0.45) and major adverse events. Weighted cumulative incidence of cardiac death was significantly higher for patients with endocarditis (p = 0.01). The composite endpoint of cardiac death and reoperation at 6 years was reduced in the Group IE (63.2 ± 6.8% vs 78.9 ± 3.1%; p = 0.022). Repair strategy resulted in an increased late survival even in IE cases. CONCLUSIONS: Data from SURTRI study report acceptable 30-day results but significantly reduced late survival in the setting of endocarditis of the tricuspid valve. Multi-disciplinary approach, repair strategy and earlier treatment may improve outcomes.

Functional Tricuspid Regurgitation: Behind the Scenes of a Long-Time Neglected Disease.

Severe tricuspid valve regurgitation has been for a long time a neglected valve disease, which has only recently attracted an increasing interest due to the notable negative impact on the prognosis of patients with cardiovascular disease. It is estimated that around 90% of tricuspid regurgitation is diagnosed as "functional" and mostly secondary to a primary left-sided heart disease and, therefore, has been usually interpreted as a benign condition that did not require a surgical management. Nevertheless, the persistence of severe tricuspid regurgitation after left-sided surgical correction of a valve disease, particularly mitral valve surgery, has been associated to adverse outcomes, worsening of the quality of life, and a significant increase in mortality rate. Similar results have been found when the impact of isolated severe tricuspid regurgitation has been studied. Current knowledge is shifting the "functional" categorization toward a more complex and detailed pathophysiological classification, identifying various phenotypes with completely different etiology, natural history and, potentially, an invasive management. The aim of this review is to offer a comprehensive guide for clinicians and surgeons with a systematic description of "functional" tricuspid regurgitation subtypes, an analysis centered on the effectiveness of existing surgical techniques and a focus on the emergent percutaneous procedures. This latter may be an attractive alternative to a standard surgical approach in patients with high-operative risk or isolated tricuspid regurgitation.

The impact of autophagy modulation on phenotype and survival of cardiac stromal cells under metabolic stress.

Cardiac stromal cells (CSCs) embrace multiple phenotypes and are a contributory factor in tissue homeostasis and repair. They can be exploited as therapeutic mediators against cardiac fibrosis and remodeling, but their survival and cardioprotective properties can be decreased by microenvironmental cues. We evaluated the impact of autophagy modulation by different pharmacological/genetic approaches on the viability and phenotype of murine CSCs, which had been subjected to nutrient deprivation or hyperglycemia, in order to mimic relevant stress conditions and risk factors of cardiovascular diseases. Our results show that autophagy is activated in CSCs by nutrient deprivation, and that autophagy induction by trehalose or autophagy-related protein 7 (ATG7)-overexpression can significantly preserve CSC viability. Furthermore, autophagy induction is associated with a higher proportion of primitive, non-activated stem cell antigen 1 (Sca1)-positive cells, and with a reduced fibrotic fraction (positive for the discoidin domain-containing receptor 2, DDR2) in the CSC pool after nutrient deprivation. Hyperglycemia, on the other hand, is associated with reduced autophagic flux in CSCs, and with a significant reduction in primitive Sca1+ cells. Autophagy induction by adenoviral-mediated ATG7-overexpression maintains a cardioprotective, anti-inflammatory and pro-angiogenic paracrine profile of CSCs exposed to hyperglycemia for 1 week. Finally, autophagy induction by ATG7-overexpression during hyperglycemia can significantly preserve cell viability in CSCs, which were subsequently exposed to nutrient deprivation, reducing hyperglycemia-induced impairment of cell resistance to stress. In conclusion, our results show that autophagy stimulation preserves CSC viability and function in response to metabolic stressors, suggesting that it may boost the beneficial functions of CSCs in cardiac repair mechanisms.

Outcome of patients undergoing isolated tricuspid repair or replacement surgery.

OBJECTIVES: The interest in isolated tricuspid valve disease has rapidly increased recently. However, clinical trials and registry data are rare in the surgical literature. This study aimed to describe the early and long-term outcomes of a real-world experience in isolated tricuspid procedures comparing repair and replacement strategies. METHODS: The Surgical-Tricuspid study is a multicentre retrospective study that enrolled adult patients who had undergone isolated tricuspid valve surgery at 13 international sites. Propensity score-matched analysis was used to compare repair versus replacement. RESULTS: A cohort of 426 patients was enrolled [mean age: 55 (16) years; 56% female]. After matching, 175 comparable pairs were analysed. Preoperative left ventricular ejection fraction was 55(9) vs 56(9) (P = 0.8) while moderate-severe tricuspid regurgitation was present in 95% of cases. The 30-day mortality rate was 4.0% vs 8.0% in the repair and replacement groups, respectively (P = 0.115). The rates of re-exploration for bleeding (6.9% vs 13.1% P = 0.050), permanent pacemaker implantation (5.1% vs 12.0%; P = 0.022) and blood transfusion (46% vs 62%; P = 0.002) were higher in the replacement group. Cumulative survival rates at 3, 5 and 7 years in the repair group were 84 (3)%, 75 (4)% and 56 (9)% vs 71 (4)%, 66 (5)% and 58 (5)% in the replacement group (P = 0.001) while cumulative incidence for reoperation at 10 years did not differ between groups [repair 10 (1)% vs replacement 9 (1)%; P = 0.469]. CONCLUSIONS: The data from the Surgical-Tricuspid study reported a high risk for patients undergoing tricuspid surgery. Isolated valve repair offered reduced early and late mortality with no difference regarding reoperation rate when compared with replacement.

Beating Versus Arrested Heart Isolated Tricuspid Valve Surgery: Long-term Outcomes.

BACKGROUND: Isolated tricuspid valve (TV) surgery is a rare procedure generally considered at high risk for perioperative mortality and poor long-term outcomes. Surgical treatment can be performed with either an arrested heart (AH) or beating heart (BH) technique. The aim of this study was to compare the outcomes of isolated tricuspid surgery with 2 different approaches. METHODS: The Surgical-Tricuspid Study is a multicenter international retrospective study enrolling adult patients who underwent isolated TV procedures (n = 406; age 56 ± 16 years; 56% female) at 13 international sites. The AH and BH strategies were performed in 253 and 153 patients, respectively. Propensity score-matched analysis was used to compare groups. RESULTS: After matching, 129 pairs were obtained and analyzed. The 30-day mortality rate was 6.2% versus 5.0% in the AH and BH groups, respectively (P = .9). The rates of acute renal failure requiring replacement therapy (10% versus 3%; P = .02) and stroke (1.6% versus 0%; P = .08) were numerically higher in the AH group. The 6-year survival rate was 67% ± 6% versus 78% ± 5% in the AH and BH groups, respectively (P = .18), whereas freedom from cardiac death was 75% ± 5% versus 84% ± 4% (P = .21). The 6-year composite cardiac end point of cardiac death and reoperation rate was 60% ± 9% versus 86% ± 5% (P = .024) comparing AH-TV replacement and BH-TV repair groups. CONCLUSIONS: Isolated TV surgery performed with a BH strategy is a safe option and resulted in a trend of increased long-term survival and freedom from reoperation compared with the standard AH technique. Patients undergoing BH valve repair had the best long-term outcome.

Operative and middle-term results of cardiac surgery in nonagenarians: a bridge toward routine practice.

BACKGROUND: Age >90 years represents in many centers an absolute contraindication to cardiac surgery. Nonagenarians are a rapidly growing subset of the population posing an expanding clinical problem. To provide helpful information in regard to this complex decision, we analyzed the operative and 5-year results of coronary and valvular surgical procedures in these patients. METHODS AND RESULTS: We retrospectively reviewed 127 patients aged >or=90 years who underwent cardiac surgery within our hospital group in the period 1998 to 2008. Kaplan-Meier and multiple logistic regression analyses were performed. A longer follow-up than most published studies and the largest series published thus far are presented. Mean age was 92 years (range, 90 to 103 years). Mean logistic EuroSCORE was 21.3+/-6.1. Sixty patients had valvular surgery (including 11 valve repairs), 49 patients had coronary artery bypass grafting, and 18 had valvular plus coronary artery bypass grafting surgery (55 left mammary artery grafts implanted). Forty-five patients (35.4%) were operated on nonelectively. Operative mortality was 13.4% (17 cases). Fifty-four patients (42.5%) had a complicated postoperative course. There were no statistically significant differences in the rate and type of complications between patient strata on the basis of type of surgery performed. Nonelective priority predicted a complicated postoperative course. Predictors of operative mortality were nonelective priority and previous myocardial infarction. Kaplan-Meier survival estimates at 5 years were comparable between patient groups on the basis of procedure performed. CONCLUSIONS: Although the rate of postoperative complications remains high, cardiac surgery in nonagenarians can achieve functional improvement at the price of considerable operative and follow-up mortality rates. Cardiac operations in these very elderly subjects are supported if appropriate selection is made and if the operation is performed earlier and electively. Our results should contribute to the development of guidelines for cardiac operations in nonagenarians.

The Treatment of Mitral Valve Disease-The Only Thing Constant is Change.

The mitral valve is without doubt the part of the human body that is most under pressure [...].

SARS-CoV-2 and Atherosclerosis: Should COVID-19 Be Recognized as a New Predisposing Cardiovascular Risk Factor?

At the beginning of the COVID-19 pandemic, the lung was recognized as the main target organ; now, new evidence suggests that SARS-CoV-2 infection leads to vascular disease. In a previous review, we supposed a bidirectional link between endothelial dysfunction and COVID-19, identifying atherosclerosis as having a crucial role in its pathogenesis. Atherosclerosis with an existing endothelial dysfunction may worsen COVID-19 manifestations, leading to adverse outcomes, as largely reported. However, COVID-19 may be the trigger factor in the progression of the atherosclerotic process up to making it clinically manifest. The thrombotic complications can involve not only the atherosclerotic plaque, but also the durability of the surgical device implanted to treat a pre-existing coronary artery disease as recently reported. The burden of the disease makes necessary a long-term stratification of patients, revising drastically targeted therapy among others.

Mitral Plasticity: The Way to Prevent the Burden of Ischemic Mitral Regurgitation?

The ischemic impairment of the left ventricular contractility, followed by an adverse remodeling leading to the displacement of the papillary muscles (PMs), increased tethering forces and loss of valve competence has been the long-term accepted definition of ischemic mitral regurgitation (IMR). Over the years, different approaches of management have attempted to address valve regurgitation, nevertheless failing to achieve satisfactory outcomes. Recent studies have observed some structural and molecular changes of the mitral valve (MV), challenging the concept of a bystander passive to the subvalvular involvement. Indeed, the solely mechanical stretch of the PMs, as in the dilated left ventricle because of the aortic valve regurgitation, is not enough in causing relevant MV regurgitation. This setting triggers a series of structural changes called "mitral plasticity," leaflets increase in their size among others, ensuring an adequate systolic area closure. In contrast, the ischemic injury not only triggers the mechanical stretch on the subvalvular apparatus but is also a powerful promotor of profibrotic processes, with an upregulation of the transforming growth factor (TGF)-ß signaling pathway, leading to a MV with exuberant leaflet thickness and impaired mobility. In this article, we revise the concept of IMR, particularly focusing on the new evidence that supports dynamic changes in the MV apparatus, discussing the consequent clinical insights of "mitral plasticity" and the potential therapeutic implications.