Multimodal imaging plays a central role in optimizing the evaluation and management of myocardial ischemia by leveraging the complementary strengths of echocardiography, cardiac magnetic resonance imaging (CMR), single photon emission computed tomography (SPECT), positron emission tomography (PET), and invasive coronary angiography (ICA). Noninvasive functional imaging is typically recommended for patients with intermediate to high pre-test probability of coronary artery disease, while coronary computed tomography angiography (CCTA) is preferred for low to intermediate risk. Stress echocardiography is valuable for detecting wall motion abnormalities and is particularly effective in multivessel or left main disease, where perfusion techniques may miss balanced ischemia. CMR offers high spatial resolution and quantitative assessment of myocardial blood flow (MBF), while SPECT and PET quantify ischemic burden, with PET providing superior accuracy for MBF and microvascular disease. ICA remains the gold standard for defining the presence, location, and severity of epicardial coronary stenosis. It is indicated when noninvasive imaging reveals high-risk features, when symptoms are refractory to medical therapy, or when noninvasive results are inconclusive. While ICA offers high spatial resolution, it alone cannot assess the hemodynamic significance of intermediate lesions, nor the coronary microvasculature. Adjunctive invasive hemodynamic and provocative coronary testing (e.g., Fractional Flow Reserve—FFR, invasive Coronary Flow Reserve—CFR, Index of Microcirculatory Resistance—IMR, acetylcholine test) provide essential insights, especially in ischemia with nonobstructive coronary arteries. Given its procedural risks, ICA should be reserved for cases where it will impact management. Intravascular imaging may be used to further characterize lesions. In summary, modality selection should be individualized based on patient characteristics, comorbidities, contraindications, and the need for anatomical versus physiological data. Integrating noninvasive and invasive modalities provides a comprehensive, patient-centered approach to ischemia evaluation.
Hypercontractile phenotype in hypertrophic cardiomyopathy indicates unfavorable hemodynamics, coronary flow and prognosis
Abstract Aims Our aim was to assess the clinical and prognostic significance of the left ventricular (LV) hypercontractile phenotype (HP) in hypertrophic cardiomyopathy (HCM), which until now remains unclear. Methods and results We enrolled 1533 HCM patients (age 51 ± 15 years, 965 males, 63%) with ejection fraction (EF) ≥ 50%, referred for rest transthoracic echocardiography (TTE) in 27 laboratories from 13 countries. Two-dimensional volumetric TTE assessment included LV outflow tract gradient (LVOTG), LV EF, and LV force (systolic blood pressure + LVOTG/ESV, mmHg/mL). HP was defined as the highest quartile of the force (> 7.32 mmHg/mL). Survival analysis was performed in a subset of 1200 patients with follow-up information. Compared with non-HP patients, HP showed higher heart rate (72 ± 14 vs. 67 ± 14 beats per minute, P < 0.001), lower stroke volume (50 ± 22 vs. 67 ± 22 mL, P < 0.001), larger left atrial volume index (44 ± 16 vs. 40 ± 16 mL/m2, P = 0.011) and higher coronary flow velocity in the mid-distal left anterior descending artery (n = 325, 41 ± 12 vs. 37 ± 14 cm/s, P = 0.021). Force was moderately related to LV EF (r = 0.48, P < 0.001) and weakly to LVOTG (r = 0.36, P < 0.001). During a median follow-up of 87 months (interquartile range 45–143 months), 131 all-cause deaths occurred. At multivariable Cox analysis, a force > 7.32 mmHg (the fourth quartile for analyzed patients) was associated with a hazard ratio of 1.44 (95% Confidence intervals 1.00–2.07) for all-cause death, independently of LVOTG and LV EF. Conclusion HP in HCM is associated with a disadvantageous systemic, cardiac and coronary hemodynamic profile as well as lower survival in the long-term.
A Machine Learning Approach to Gene Expression in Hypertrophic Cardiomyopathy
Background/Objectives: Hypertrophic cardiomyopathy (HCM) is a common heart disorder characterized by the thickening of the heart muscle, particularly in the left ventricle, which increases the risk of cardiac complications. This study aims to analyze the expression of apoptosis-regulating genes (CASP8, CASP9, CASP3, BAX, and BCL2) in blood samples from HCM patients, to better understand their potential as biomarkers for disease progression. Methods: Quantitative real-time PCR (qPCR) was used to evaluate gene expression in blood samples from 93 HCM patients. The correlation between apoptosis-regulating genes was conducted and clinical parameters were integrated for feature importance and clustering analysis. Results: Most patients exhibited significant downregulation of CASP8, CASP9, and CASP3. In contrast, BAX expression was elevated in 71 out of 93 patients, while BCL2 was increased in 55 out of 93 patients. Correlation analysis revealed weak negative correlations between the BAX/BCL2 ratio and CASP gene expression. Conclusions: These findings suggest that reduced expression of apoptotic genes may indicate a protective cellular mechanism, which could serve as a biomarker for disease progression. Further studies are needed to investigate the potential for therapeutic modulation of these pathways to improve patient outcomes.
The Role of Cardiopulmonary Exercise Testing in Hypertrophic Cardiomyopathy
This review emphasizes the importance of cardiopulmonary exercise testing (CPET) in patients diagnosed with hypertrophic cardiomyopathy (HCM). In contrast to standard exercise testing and stress echoes, which are limited due to the ECG changes and wall motion abnormalities that characterize this condition, CPET allows for the assessment of the complex pathophysiology and severity of the disease, its mechanisms of functional limitation, and its risk stratification. It is useful tool to evaluate the risk for sudden cardiac death and select patients for cardiac resynchronization therapy (CRT), cardiac transplantation, or mechanical circulatory support, especially when symptomatology and functional status are uncertain. It may help in differentiating HCM from other forms of cardiac hypertrophy, such as athletes’ heart. Finally, it is used to guide and monitor therapy as well as for exercise prescription. It may be considered every 2 years in clinically stable patients or every year in patients with worsening symptoms. Although performed only in specialized centers, CPET combined with echocardiography (i.e., CPET imaging) and invasive CPET are more informative and provide a better assessment of cardiac functional status, left ventricular outflow tract obstruction, and diastolic dysfunction during exercise in patients with HCM.
Stress Echo 2030: The Novel ABCDE-(FGLPR) Protocol to Define the Future of Imaging
With stress echo (SE) 2020 study, a new standard of practice in stress imaging was developed and disseminated: the ABCDE protocol for functional testing within and beyond CAD. ABCDE protocol was the fruit of SE 2020, and is the seed of SE 2030, which is articulated in 12 projects: 1-SE in coronary artery disease (SECAD); 2-SE in diastolic heart failure (SEDIA); 3-SE in hypertrophic cardiomyopathy (SEHCA); 4-SE post-chest radiotherapy and chemotherapy (SERA); 5-Artificial intelligence SE evaluation (AI-SEE); 6-Environmental stress echocardiography and air pollution (ESTER); 7-SE in repaired Tetralogy of Fallot (SETOF); 8-SE in post-COVID-19 (SECOV); 9: Recovery by stress echo of conventionally unfit donor good hearts (RESURGE); 10-SE for mitral ischemic regurgitation (SEMIR); 11-SE in valvular heart disease (SEVA); 12-SE for coronary vasospasm (SESPASM). The study aims to recruit in the next 5 years (2021–2025) ≥10,000 patients followed for ≥5 years (up to 2030) from ≥20 quality-controlled laboratories from ≥10 countries. In this COVID-19 era of sustainable health care delivery, SE2030 will provide the evidence to finally recommend SE as the optimal and versatile imaging modality for functional testing anywhere, any time, and in any patient.
Hemodynamic Heterogeneity of Reduced Cardiac Reserve Unmasked by Volumetric Exercise Echocardiography
Background: Two-dimensional volumetric exercise stress echocardiography (ESE) provides an integrated view of left ventricular (LV) preload reserve through end-diastolic volume (EDV) and LV contractile reserve (LVCR) through end-systolic volume (ESV) changes. Purpose: To assess the dependence of cardiac reserve upon LVCR, EDV, and heart rate (HR) during ESE. Methods: We prospectively performed semi-supine bicycle or treadmill ESE in 1344 patients (age 59.8 ± 11.4 years; ejection fraction = 63 ± 8%) referred for known or suspected coronary artery disease. All patients had negative ESE by wall motion criteria. EDV and ESV were measured by biplane Simpson rule with 2-dimensional echocardiography. Cardiac index reserve was identified by peak-rest value. LVCR was the stress-rest ratio of force (systolic blood pressure by cuff sphygmomanometer/ESV, abnormal values ≤2.0). Preload reserve was defined by an increase in EDV. Cardiac index was calculated as stroke volume index * HR (by EKG). HR reserve (stress/rest ratio) <1.85 identified chronotropic incompetence. Results: Of the 1344 patients, 448 were in the lowest tertile of cardiac index reserve with stress. Of them, 303 (67.6%) achieved HR reserve <1.85; 252 (56.3%) had an abnormal LVCR and 341 (76.1%) a reduction of preload reserve, with 446 patients (99.6%) showing ≥1 abnormality. At binary logistic regression analysis, reduced preload reserve (odds ratio [OR]: 5.610; 95% confidence intervals [CI]: 4.025 to 7.821), chronotropic incompetence (OR: 3.923, 95% CI: 2.915 to 5.279), and abnormal LVCR (OR: 1.579; 95% CI: 1.105 to 2.259) were independently associated with lowest tertile of cardiac index reserve at peak stress. Conclusions: Heart rate assessment and volumetric echocardiography during ESE identify the heterogeneity of hemodynamic phenotypes of impaired chronotropic, preload or LVCR underlying a reduced cardiac reserve.