Cardiac magnetic resonance imaging in the evaluation and management of mitral valve prolapse - a comprehensive review.

Mitral valve prolapse is a common valve disorder that usually has a benign prognosis unless there is significant regurgitation or LV impairment. However, a subset of patients are at an increased risk of ventricular arrhythmias and sudden cardiac death, which has led to the recognition of "arrhythmic mitral valve prolapse" as a clinical entity. Emerging risk factors include mitral annular disjunction and myocardial fibrosis. While echocardiography remains the primary method of evaluation, cardiac magnetic resonance has become crucial in managing this condition. Cine magnetic resonance sequences provide accurate characterization of prolapse and annular disjunction, assessment of ventricular volumes and function, identification of early dysfunction and remodeling, and quantitative assessment of mitral regurgitation when integrated with flow imaging. However, the unique strength of magnetic resonance lies in its ability to identify tissue changes. T1 mapping sequences identify diffuse fibrosis, in turn related to early ventricular dysfunction and remodeling. Late gadolinium enhancement sequences detect replacement fibrosis, an independent risk factor for ventricular arrhythmias and sudden cardiac death. There are consensus documents and reviews on the use of cardiac magnetic resonance specifically in arrhythmic mitral valve prolapse. However, in this article, we propose an algorithm for the broader use of cardiac magnetic resonance in managing this condition in various scenarios. Future advancements may involve implementing techniques for tissue characterization and flow analysis, such as 4D flow imaging, to identify patients with ventricular dysfunction and remodeling, increased arrhythmic risk, and more accurate grading of mitral regurgitation, ultimately benefiting patient selection for surgical therapy.

"Lambda-wave" ST-elevation is associated with severe prognosis in stress (takotsubo) cardiomyopathy.

BACKGROUND: Persistent ST-segment elevation in acute coronary syndrome is associated with both short and long-term complications. By contrast, there is limited information about ST-elevation and its evolution during takotsubo (stress) cardiomyopathy (TTC). AIM: To evaluate whether persistent downsloping ST-elevation in the early stages of TTC might correlate with short and long-term clinical events. METHODS: One-hundred fifty-eight consecutive subjects with TTC were prospectively enrolled and assessed by electrocardiogram. Patients were classified in two groups according to the presence of downsloping ST-elevation ≥5 mm lasting at least 24 hr ("lambda-wave" ST-elevation group vs. without downsloping ST-elevation) in at least one/two contiguous leads. RESULTS: Five (3.2%) patients, all female with a mean left ventricular ejection fraction 32 ± 5%, were included in the lambda-wave ST-elevation group. These patients were characterized by a higher prevalence of physical stressor (100% vs. 49%, p = 0.04) and higher admission and peak levels of troponin-I levels during hospitalization. Peak of ST-elevation in the lambda-wave ST-elevation group was reached 6 hr after admission and gradually decreased after 24 hr. In-hospital complications were observed in all the patients presenting lambda ST-elevation (100% vs. 23%, p = 0.03, OR: 29.1, p = 0.04); one patient presented endoventricular thrombosis and two died of cardiogenic shock. At long-term follow-up (mean 443 days), adverse events were observed in 80% of patients with lambda-wave ST-elevation (RR of adverse events at follow-up 32, p < 0.01). CONCLUSION: Persistent downsloping lambda-wave ST-elevation during the acute phase of stress cardiomyopathy may be associated with a higher risk of adverse events at short and long-term follow-up.

Renal impairment and outcome in patients with takotsubo cardiomyopathy.

OBJECTIVES: The objectives were to ascertain the prevalence of renal impairment among patients with a takotsubo cardiomyopathy (TTC) episode and whether clinical outcomes are related to renal function. METHODS: A total of 108 consecutive subjects with TTC were enrolled in a multicenter registry and followed for a mean period of 429 days. Renal function was evaluated during hospitalization in terms of acute kidney injury/failure and estimated glomerular filtration rate (eGFR). Incidence of death, rehospitalization, and recurrence of TTC during follow-up was recorded. RESULTS: Raised creatinine levels can be found during hospitalizations for TTC episodes (analysis of variance P<.001). Incidence of acute kidney injury was 10%; that of acute kidney failure was 1%. Admission eGFR levels were proportional to the duration of hospitalization (r = -0.28, P<.01). Estimated GFR nadir values were related to adverse events at follow-up (log-rank P<.001). The hazard ratio of adverse events at follow-up in subjects with severe renal impairment (nadir eGFR <30 mL/[min 1.73 m(2)]) vs those with eGFR >60 mL/(min 1.73 m(2)) was 1.817 (95% confidence interval, 1.097-3.009; P<.05). CONCLUSIONS: Raised creatinine levels and impaired renal function may be found in patients with TTC. Lower eGFR values during hospitalization are associated with longer hospitalizations and higher rates of adverse events at follow-up. Renal function during a TTC episode should be carefully evaluated.

Transcatheter mitral valve repair for the treatment of severe mitral regurgitation and exertional pre-syncope in a patient with non-obstructive hypertrophic cardiomyopathy: a case report.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) has a complex pathophysiology and heterogeneous phenotypic expression. In obstructive HCM with significant mitral regurgitation (MR), MitraClip device implantation reduces MR severity and symptoms. There are no data regarding MitraClip implantation in patients with non-obstructive HCM and significant MR. CASE SUMMARY: A 78-year-old woman with non-obstructive HCM and significant functional MR (3+) was admitted to our centre for dyspnoea and episodes of pre-syncope under light stress. Transthoracic and transoesophageal echocardiography showed a normal left ventricular ejection fraction and normal right heart pressures, an inverted mitral filling pattern, and a central prevalent jet (A2-P2 origin) of MR. Exercise echocardiography performed to verify exercise tolerance was interrupted at the 50-W stage due to severe hypotension and pre-syncope. After transcatheter edge-to-edge repair using the MitraClip system, the patient exhibited a reduction in MR Grade from 3+ to 1+. Follow-up up to 1-year post-procedure revealed noticeable improvements in exercise tolerance and symptoms. There were no further episodes of pre-syncope. DISCUSSION: In non-obstructive HCM, the pathophysiological role of MR in symptom generation is unknown. In this patient, we speculated that significant MR contributed to the mechanisms responsible for severe hypotension and pre-syncope during exercise. A reduction in MR after MitraClip implantation was associated with symptomatic improvements. Our findings further highlight the potential utility of the exercise stress test in therapeutic decision-making for patients with non-obstructive HCM and MR.