Clinical characteristics and prognosis of 60 patients with midventricular obstructive hypertrophic cardiomyopathy

Outcomes of concomitant myectomy and left ventricular apical aneurysm repair in patients with hypertrophic cardiomyopathy

OBJECTIVES

Hypertrophic cardiomyopathy with left ventricular apical aneurysm is a phenotype associated with a 4-fold increase in the risk for sudden cardiac death. In this study, we describe the surgical outcome of concomitant apical aneurysm repair in patients undergoing transapical myectomy for hypertrophic cardiomyopathy.

METHODS

We identified 67 patients with left ventricular apical aneurysms who underwent transapical myectomy and apical aneurysm repair between July 2000 and August 2020. Long-term survival was compared with that of 2746 consecutive patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy with subaortic obstruction.

RESULTS

Transapical myectomy was indicated for midventricular obstruction (n = 44) or left ventricular remodeling for diastolic heart failure (n = 29). Preoperatively, 74.6% (n = 50) of patients were in New York Heart Association class III/IV heart failure, and 34.3% (n = 23) of patients had experienced syncope or presyncope. Atrial fibrillation was documented in 22 patients (32.8%), and episodes of ventricular arrhythmias were recorded in 30 patients (44.8%). Thrombus was present in the apical aneurysm in 6 patients. During a median (interquartile range) follow-up of 4.9 (1.8-7.6) years, the estimated 1- and 5-year survivals were 98.5% and 94.5%, respectively, which were not significantly different from that of patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy (P = .52) or an age- and sex-matched US general population (P = .40).

CONCLUSIONS

Apical aneurysm repair in conjunction with septal myectomy is a safe procedure, and the good long-term survival of patients suggests that the procedure may reduce cardiac-related death in this high-risk hypertrophic cardiomyopathy population.

Left Atrial Dysfunction in Apical Hypertrophic Cardiomyopathy: Assessed by Cardiovascular Magnetic Resonance Feature-tracking

PURPOSE

To evaluate the left atrial (LA) function in participants with apical hypertrophic cardiomyopathy (AHCM) by cardiovascular magnetic resonance feature tracking (CMR-FT).

MATERIALS AND METHODS

Thirty typical AHCM (TAHCM) patients, 23 subclinical AHCM (SAHCM) patients and 32 normal healthy volunteers who underwent CMR exam were retrospectively analyzed. LA reservoir, conduit, and contractile function were quantified by volumetric and CMR-FT derived strain and strain rate (SR) parameters from 2-chamber and 4-chamber cine imaging.

RESULTS

Compared with healthy participants, both TAHCM and SAHCM patients had impaired LA reservoir function (total strain [%]: TAHCM 31.3±12.2, SAHCM 31.8±12.3, controls 40.4±10.7, P <0.01; total SR [/s]: TAHCM 1.1±0.4, SAHCM 1.1±0.5, controls 1.4 ± 0.4, P <0.01) and conduit function (passive strain [%]: TAHCM 14.4±7.6, SAHCM 16.4±8.8, controls 23.3±8.1, P <0.01; passive SR [/s]: TAHCM -0.5±0.3, SAHCM -0.6±0.3, controls -1.0±0.4, P <0.01). Regarding contraction function, although TAHCM and SAHCM patients had preserved active emptying fraction and strain (all P >0.05), patients with TAHCM had the lowest active SR value among the 3 groups ( P= 0.03). LA reservoir and conduit strain were both significantly associated with left ventricular mass index and maximal wall thickness (all P <0.05). A moderate correlation between LA passive SR and left ventricular cardiac index ( P <0.01).

CONCLUSIONS

The LA reservoir and conduit function are predominately impaired and appeared in both SAHCM and TAHCM patients.

Prognostic role of left ventricular apical aneurysm in hypertrophic cardiomyopathy: A systematic review and meta-analysis

OBJECTIVES

The aim of this study was to systematically review and quantitatively synthesize existing evidence about the prognostic value of LV apical aneurysm in patients with HCM.

BACKGROUND

Hypertrophic cardiomyopathy (HCM) represents a common inherited heart disease associated with enormous diversity in morphologic expression and clinical course. With the increasing penetration of advanced high resolution cardiovascular imaging into routine HCM practice, a subset of HCM patients with left ventricular (LV) apical aneurysm have become more widely recognized.

METHODS

Medline was searched for studies describing the prognostic implication of LV apical aneurysm in patients with HCM. In the main analysis the combined endpoint of major HCM-related outcomes was assessed. Separate analyses for sudden cardiac death (SCD) events and thromboembolic events were also performed.

RESULTS

Six studies comprising of 2382 patients met the inclusion criteria. In the pooled analysis, the presence of LV apical aneurysm was significantly associated with major adverse outcomes (pooled OR: 5.13, 95 CI: 2.85 to 9.23, I²:31%), increased risk of SCD arrhythmic events (pooled OR: 4.67, 95% CI: 2.30 to 9.48, I²: 38%) and thromboembolic events (pooled OR: 6.30, 95% CI: 1.52 to 26.19, I²: 66%).

CONCLUSIONS

These data demonstrate that LV apical aneurysm in HCM patients is associated with an increased risk for SCD events and thromboembolism. This finding might encourage the inclusion of LV apical aneurysm into the HCM SCD risk stratification algorithm as a novel risk marker that supports consideration for primary prevention implantable cardioverter defibrillator and anticoagulation for stroke prophylaxis.

Mid-ventricular obstruction is associated with non-sustained ventricular tachycardia in patients with hypertrophic obstructive cardiomyopathy

Background

Mid‐ventricular obstruction (MVO) is a rare subtype of hypertrophic cardiomyopathy (HCM) but it is associated with ventricular arrhythmia. The relationship between MVO and non‐sustained ventricular tachycardia (NSVT) in HCM patients is unknown.

Hypothesis

The severity of MVO increases the incidence of NSVT in patients with hypertrophic obstructive cardiomyopathy (HOCM).

Methods

Five hundred and seventy‐two consecutive patients diagnosed with HOCM in Fuwai Hospital between January 2015 and December 2017 were enrolled in this study. Holter electrocardiographic and clinical parameters were compared between HOCM patients with and without MVO.

Results

Seventy‐six (13.3%) of 572 patients were diagnosed with MVO. Compared to patients without MVO, those with MVO were much younger, and had a higher incidence of syncope, greater left ventricular (LV) posterior wall thickness, a higher percentage of LV late gadolinium enhancement, and higher prevalence of NSVT. Furthermore, the prevalence of NSVT increased with the severity of MVO (without, mild, moderate or severe: 11.1%, 18.2%, 25.6%, respectively, p for trend < .01). Similarly, the prevalence of NSVT differed among patients with isolated LV outflow tract (LVOTO), both MVO and LVOTO, and isolated MVO (11.1%, 21.3%, 26.6%, respectively, p for trend = .018). In addition to age, diabetes, left atrial diameter, and maximal wall thickness, multivariate analysis revealed the presence of MVO as an independent risk factor for NSVT (Odds ratio 2.69; 95% confidence interval 1.41 to 5.13, p = .003).

Conclusions

The presence and severity of MVO was associated with higher incidence of NSVT in HOCM patients.

Permanent Pacing in a Patient with Left Ventricular Mid-Cavity Obstruction and Apical Aneurysm

Hypertrophic cardiomyopathy with left ventricular (LV) mid-cavity obstruction and LV apical aneurysm is associated with high morbidity and mortality rates. However, consensus is lacking on the treatment modality for LV mid-cavity obstruction and LV apical aneurysm. Here, we report a case of reduced LV mid-cavity pressure gradient and symptoms, treated using permanent pacing. The effect of permanent pacing on pressure gradient and symptoms lasted for 4 years. As pacing is relatively non-invasive compared to surgical therapy, permanent pacing is a good option, especially in the elderly patients with LV mid-cavity obstruction and apical aneurysm.

Mid-ventricular obstructive hypertrophic cardiomyopathy with apical aneurysm: An important subtype of arrhythmogenic cardiomyopathy

Mid-ventricular obstructive hypertrophic cardiomyopathy (MVOHCM) is an uncommon type of HCM. LV apical aneurysms are present in more than 20% MVOHCM cases and has been identified as an independent predictor of potentially lethal arrhythmic events, including non-sustained or sustained ventricular tachycardia (VT), and ventricular fibrillation (VF), as well as SCD. Although the pathogenesis of LVA remains unknown, but it has been suggested that apical aneurysm may be secondary to the increased after-load and high apical pressure arising from significant pressure gradient of the midventricular obstruction. The scarred rim of the aneurysm and the adjacent areas of LV myocardial fibrosis and consequent apical oxygen-demand mismatch may be responsible for the formation of apical aneurysm. Recent electrophysiologic studies have demonstrated that the aneurysmal rim forms the primary culprit arrhythmogenic substrate for generation of monomorphic ventricular tachycardia leading to SCD, but the clinical significance of the size of aneurysm in relation to SCD remains unsettled. We summarized the clinical features of the patients with MVOHCM and apical aneurysms. Appropriate therapeutic interventions include ICD implantation, and early surgical intervention for gradient relief may be undertaken to relief the MVO.

Left ventricular aneurysms in hypertrophic cardiomyopathy with midventricular obstruction: A systematic review of literature

BACKGROUND

Hypertrophic cardiomyopathy (HCM) with or without left ventricular apical aneurysm (LVA) had been studied in the past. Midventricular obstruction associated with HCM and LVA is a unique entity that has not been distinguished previously as a separate phenotypic disease in HCM patients.

METHODS

A systematic review of Pubmed and Google Scholar was conducted from inception until September 2017 for all observational studies conducted on HCM with midventricular obstruction and LVA.

RESULTS

A total of 94 patients from 39 studies were included in our analysis. The mean age of the patients was 58.05 ± 11.76 years with 59.6% being males. The most common electrocardiographic finding was T wave inversion occurring in 13.8% of the cases followed by ST elevation (9.5%). Maximal left ventricle (LV) wall thickness was reported 18.89 ± 5.19 mm on transthoracic echocardiography and paradoxical jet flow was detected in 29.8% of patients. Beta-blockers (58.5%) were the most common drug therapy at baseline and amiodarone (10.6%) was the most common antiarrhythmic used for ventricular tachycardia (VT). The most common complication, VT, occurred in 39.3% of cases and the incidence of all-cause mortality was 13.8 % over 16 ± 20.1 months follow-up. Implantable cardioverter defibrillator (ICD) was used in 37.2% of patients; 25.7% of patients with ICD received appropriate shock therapy.

CONCLUSION

HCM with LVA and midventricular obstruction is a unique entity that appears to be associated with high incidence of morbidity and mortality. Thus, early diagnosis and therapeutic intervention is recommended for management of this condition.

Long-Term Prognosis after Myectomy in Hypertrophic Obstructive Cardiomyopathy with Severe Left Ventricular Hypertrophy

Objectives: Patients with hypertrophic obstructive cardiomyopathy (HOCM) and severe left ventricular hypertrophy (maximal left ventricular wall thickness ≥30 mm) are at high risk of sudden cardiac death (SCD). In this study, we aimed to determine whether HOCM patients with severe hypertrophy had a lower incidence of SCD after myectomy. Methods: HOCM patients with severe hypertrophy were consecutively enrolled from Fuwai Hospital in China between 2000 and 2013. Long-term outcomes were retrospectively compared between the 2 groups, namely the myectomy group and medical group. Results: A total of 244 patients (118 in the myectomy group and 126 in the medical group) were involved. The mean follow-up durations for the myectomy and medical groups were 5.07 ± 3.73 and 6.23 ± 4.15 years, respectively. During the follow-up period, the annual cardiovascular mortality rate was 0.84% in the myectomy group and 2.04% in the medical group (p = 0.041). The annual SCD rate was 0.33% in the myectomy group and 1.40% in the medical group (p = 0.040). Multivariate Cox regression analysis showed that myectomy was independently associated with lower rates of cardiovascular death and SCD. Conclusions: In HOCM patients with severe hypertrophy, those that underwent myectomy had a lower risk of cardiovascular death and SCD than those treated with medicines only.