Different Histopathologic Diagnoses in Patients With Clinically Diagnosed Hypertrophic Cardiomyopathy After Surgical Myectomy

Austrian consensus statement on the diagnosis and management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease that is characterized by left ventricular hypertrophy unexplained by secondary causes. Based on international epidemiological data, around 20,000-40,000 patients are expected to be affected in Austria. Due to the wide variety of clinical and morphological manifestations the diagnosis can be difficult and the disease therefore often goes unrecognized. HCM is associated with a substantial reduction in quality of life and can lead to sudden cardiac death, especially in younger patients. Early and correct diagnosis, including genetic testing, is essential for comprehensive counselling of patients and their families and for effective treatment. The latter is especially true as an effective treatment of outflow tract obstruction has recently become available in the form of a first in class cardiac myosin ATPase inhibitor, as a noninvasive alternative to established septal reduction therapies. The aim of this Austrian consensus statement is to summarize the recommendations of international guidelines with respect to the genetic background, pathophysiology, diagnostics and management in the context of the Austrian healthcare system and resources, and to present them in easy to understand algorithms.

The Expansion of Genetic Testing in Cardiovascular Medicine: Preparing the Cardiology Community for the Changing Landscape

PURPOSE OF REVIEW

Pathogenic DNA variants underlie many cardiovascular disease phenotypes. The most well-recognized of these include familial dyslipidemias, cardiomyopathies, arrhythmias, and aortopathies. The clinical presentations of monogenic forms of cardiovascular disease are often indistinguishable from those with complex genetic and non-genetic etiologies, making genetic testing an essential aid to precision diagnosis.

RECENT FINDINGS

Precision diagnosis enables efficient management, appropriate use of emerging targeted therapies, and follow-up of at-risk family members. Genetic testing for these conditions is widely available but under-utilized. In this review, we summarize the potential benefits of genetic testing, highlighting the specific cardiovascular disease phenotypes in which genetic testing should be considered, and how clinicians can integrate guideline-directed genetic testing into their practice.

Imaging cardiac hypertrophy in hypertrophic cardiomyopathy and its differential diagnosis

PURPOSE OF REVIEW

The aim of this study was to review imaging of myocardial hypertrophy in hypertrophic cardiomyopathy (HCM) and its phenocopies. The introduction of cardiac myosin inhibitors in HCM has emphasized the need for careful evaluation of the underlying cause of myocardial hypertrophy.

RECENT FINDINGS

Advances in imaging of myocardial hypertrophy have focused on improving precision, diagnosis, and predicting prognosis. From improved assessment of myocardial mass and function, to assessing myocardial fibrosis without the use of gadolinium, imaging continues to be the primary tool in understanding myocardial hypertrophy and its downstream effects. Advances in differentiating athlete's heart from HCM are noted, and the increasing rate of diagnosis in cardiac amyloidosis using noninvasive approaches is especially highlighted due to the implications on treatment approach. Finally, recent data on Fabry disease are shared as well as differentiating other phenocopies from HCM.

SUMMARY

Imaging hypertrophy in HCM and ruling out other phenocopies is central to the care of patients with HCM. This space will continue to rapidly evolve, as disease-modifying therapies are under investigation and being advanced to the clinic.

Beta-Blocker Exposure and Survival in Patients With Transthyretin Amyloid Cardiomyopathy

OBJECTIVE

To investigate a potential association between beta-blocker exposure and survival in patients with transthyretin amyloid cardiomyopathy (ATTR-CM).

METHODS

In this real-world prospective registry of 128 consecutive patients with ATTR-CM recruited in 7 institutions in Galicia (Spain), survival of 65 patients who received beta blockers on registry enrollment was compared with that of 63 untreated controls by means of both unweighted Cox regression and Cox regression with inverse probability of treatment weighting. Tolerance to and adverse effects of beta blockers were recorded. Median study follow-up was 520 days.

RESULTS

Patients with ATTR-CM who received beta blockers showed statistically significant lower all-cause mortality than untreated controls as evaluated by either unweighted Cox regression (hazard ratio, 0.31; 95% CI, 0.12 to 0.79) or Cox regression with inverse probability of treatment weighting (hazard ratio, 0.18; 95% CI, 0.08 to 0.41; P<.001). Several sensitivity analyses confirmed the internal validity of these results. The overall frequency of beta-blocker suspension due to adverse effects was 25% (95% CI, 15.5% to 34.5%).

CONCLUSION

In this real-world, prospective, multi-institutional registry, patients with ATTR-CM who received beta blockers had lower all-cause mortality than untreated controls.

Outcomes in Patients With Obstructive Hypertrophic Cardiomyopathy and Concomitant Aortic Stenosis Undergoing Surgical Myectomy and Aortic Valve Replacement

Background Hypertrophic cardiomyopathy (HCM) and aortic stenosis can cause obstruction to the flow of blood out of the left ventricular outflow tract into the aorta, with obstructive HCM resulting in dynamic left ventricular outflow tract obstruction and moderate or severe aortic stenosis causing fixed obstruction caused by calcific degeneration. We sought to report the characteristics and longer-term outcomes of patients with severe obstructive HCM who also had concomitant moderate or severe aortic stenosis requiring surgical myectomy and aortic valve replacement. Methods and Results We studied 191 consecutive patients (age 67±6 years, 52% men) who underwent myectomy and aortic valve (AV) replacement (90% bioprosthesis) at our center between June 2002 and June 2018. Clinical and echo data including left ventricular outflow tract gradient and indexed AV area were recorded. The primary outcome was death. Prevalence of hypertension (63%) and hyperlipidemia (75%) were high, with a Society of Thoracic Surgeons score of 5±4, and 70% of participants had no HCM-related sudden death risk factors. Basal septal thickness and indexed AV area were 1.9±0.4 cm and 0.72±0.2 cm²/m², respectively, while 100% of patients had dynamic left ventricular outflow tract gradient >50 mm Hg. At 6.5±4 years, 52 (27%) patients died (1.5% in-hospital deaths). One-, 2-, and 5-year survival in the current study sample was 94%, 91%, and 83%, respectively, similar to an age-sex-matched general US population. On multivariate Cox survival analysis, age (hazard ratio [HR], 1.65; 95% CI, 1.24-2.18), chronic kidney disease (HR, 1.58; 95% CI, 1.21-2.32), and right ventricular systolic pressure on preoperative echocardiography (HR, 1.28; 95% CI, 1.05-1.57) were associated with longer-term mortality, but traditional HCM risk factors did not. Conclusions In symptomatic patients with severely obstructive HCM and moderate or severe aortic stenosis undergoing a combined surgical myectomy and AV replacement at our center, the observed postoperative mortality was significantly lower than the expected mortality, and the longer-term survival was similar to a normal age-sex-matched US population.

Multimodality Imaging in Cardiac Amyloidosis

PURPOSE OF REVIEW

Cardiac amyloidosis is an increasingly recognized condition with a growing range of targeted therapies, but diagnosis requires a high index of suspicion and multimodality imaging expertise. Early diagnosis remains key to improving quality of life and survival. This article reviews the multimodality imaging approach to the diagnosis, differentiation, and prognosis of cardiac amyloidosis.

RECENT FINDINGS

Recent advances in multimodality cardiac imaging have allowed for earlier diagnosis of cardiac amyloidosis resulting in earlier initiation of life-saving therapy in cases of light chain amyloidosis and life-prolonging therapy in transthyretin amyloidosis. With these advances in multimodality imaging, it is important for cardiologists and cardiac imagers to be aware of the subtleties of early disease, the appropriate diagnostic approach as well as understanding the practicalities and pitfalls that are encountered with each modality.

Characteristics and Outcomes of Elderly Patients With Hypertrophic Cardiomyopathy

Background

We report characteristics and outcomes of elderly patients with hypertrophic cardiomyopathy (HCM) with basal septal hypertrophy and dynamic left ventricular outflow tract obstruction.

Methods and Results

We studied 1110 consecutive elderly patients with HCM (excluding moderate or greater aortic stenosis or subaortic membrane, age 80±5 years [range, 75–92 years], 66% women), evaluated at our center between June 2002 and December 2018. Clinical and echocardiographic data, including maximal left ventricular outflow tract gradient, were recorded. The primary outcome was death and appropriate internal defibrillator discharge. Hypertension was observed in 72%, with a Society of Thoracic Surgeons (STS) score (8.6±6); while 80% had no HCM‐related sudden cardiac death risk factors. Left ventricular mass index, basal septal thickness, and maximal left ventricular outflow tract gradient were 127±43 g/m², 1.7±0.4 cm, and 49±31 mm Hg, respectively. A total of 597 (54%) had a left ventricular outflow tract gradient >30 mm Hg, of which 195 (33%) underwent septal reduction therapy (SRT; 79% myectomy and 21% alcohol ablation). At 5.1±4 years, 556 (50%) had composite events (273 [53%] in nonobstructive, 220 [55%] in obstructive without SRT, and 63 [32%] in obstructive subgroup with SRT). One‐ and 5‐year survival, respectively were 93% and 63% in nonobstructive, 90% and 63% in obstructive subgroup without SRT, and 94% and 84% in the obstructive subgroup with SRT. Following SRT, there were 5 (2.5%) in‐hospital deaths (versus an expected Society of Thoracic Surgeons mortality of 9.2%).

Conclusions

Elderly patients with HCM have a high prevalence of traditional cardiovascular rather than HCM risk factors. Longer‐term outcomes of the obstructive SRT subgroup were similar to a normal age‐sex matched US population.

Fractal Analysis: Prognostic Value of Left Ventricular Trabecular Complexity Cardiovascular MRI in Participants with Hypertrophic Cardiomyopathy

Background The prognostic value of myocardial trabecular complexity in patients with hypertrophic cardiomyopathy (HCM) is unknown. Purpose To explore the prognostic value of myocardial trabecular complexity using fractal analysis in participants with HCM. Materials and Methods The authors prospectively enrolled participants with HCM who underwent 3.0-T cardiovascular MRI from August 2011 to October 2017. The authors also enrolled 100 age- and sex-matched healthy participants to form a comparison group. Trabeculae were quantified with fractal analysis of cine slices to estimate the fractal dimension (FD). Participants with HCM were divided into normal and high FD groups according to the upper limit of normal reference value from the healthy group. The primary end point was defined as all-cause mortality and aborted sudden cardiac death. The secondary end point was the composite of the primary end point and readmission to the hospital owing to heart failure. Internal validation was performed using the bootstrapping method. Results A total of 378 participants with HCM (median age, 50 years; age range, 40-61 years; 207 men) and 100 healthy participants (median age, 46 years; age range, 36-59 years; 55 women) were included in this study. During the median follow-up of 33 months ± 18 (standard deviation), the increased maximal apical FD (≥1.325) had a higher risk of the primary and secondary end points than those with a normal FD (<1.325) (P = .01 and P = .04, respectively). Furthermore, Cox analysis revealed that left ventricular maximal apical FD (hazard ratio range, 1.001-1.008; all P < .05) provided significant prognostic value to predict the primary and secondary end points after adjustment for the European Society of Cardiology predictors and late gadolinium enhancement. Internal validation showed that left ventricular maximal apical FD retained a good performance in predicting the primary end points with an area under the curve of 0.70 ± 0.03. Conclusion Left ventricular apical fractal dimension, which reflects myocardial trabecular complexity, was an independent predictor of the primary and secondary end points in patients with hypertrophic cardiomyopathy. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Captur and Moon in this issue.

Cardiac AA amyloidosis in a patient with obstructive hypertrophic cardiomyopathy

Cardiac amyloid A (AA) amyloidosis is rare. We present the case of a 72-year-old woman with obstructive hypertrophic cardiomyopathy (HCM) and biopsy-proven renal AA amyloidosis whose dyspnea and exercise intolerance had worsened over the previous year. Her AA amyloidosis was suspected to be secondary to chronic diverticulitis for which she had undergone hemicolectomy and sigmoidectomy 3 years prior. Echocardiographic findings were consistent with worsening left ventricular outflow tract obstruction at rest. Cardiac magnetic resonance imaging revealed patchy areas of midwall late gadolinium enhancement. Right ventricular endomyocardial biopsy did not reveal amyloid deposition, and cardiac technetium-99m pyrophosphate scintigraphy did not suggest transthyretin amyloidosis. The patient underwent septal myectomy with resection of an accessory papillary muscle. Pathological examination of the myectomy specimen was consistent with HCM. In addition, there was a thick layer of diffuse endocardial and vascular amyloid deposition that was identified as AA type by laser-microdissection with liquid chromatography-coupled tandem-mass spectrometry. This case report highlights the presence of 2 distinct disease processes occurring simultaneously and the importance of tissue diagnosis of AA amyloidosis, a condition that is not commonly associated with HCM.