Exercise-Stress Echocardiography and Effort Intolerance in Asymptomatic/Minimally Symptomatic Patients With Degenerative Mitral Regurgitation Combined Invasive–Noninvasive Hemodynamic Monitoring

The prognostic relevance of exercise pulmonary hypertension in cardiac and pulmonary diseases

PURPOSE OF REVIEW

In this review, we provide an overview of the prognostic implications of exPH in patients with various common cardiac and pulmonary diseases.

RECENT FINDINGS

Exercise pulmonary hypertension (exPH) has been recently re-introduced in the current European Society of Cardiology/European Respiratory Society pulmonary hypertension guidelines. Accordingly, exPH is defined as a mean pulmonary arterial pressure (mPAP)/cardiac output ( CO ) slope greater than 3 mmHg/l/min. Key considerations for this re-introduction included increasing understanding on normal pulmonary hemodynamics during exercise and the broadly available evidence on the association of an abnormal mPAP/ CO slope with poor survival in the general population and in different disease entities.

SUMMARY

Exercise (patho-)physiology has opened a new field for clinical research facilitating recognition of cardiovascular and pulmonary vascular diseases in an early stage. Such early recognition with significant prognostic and possibly therapeutic relevance, but being undetectable at rest, makes exercise pulmonary hemodynamics particularly interesting for common diseases, such as valvular heart disease, left heart disease, and chronic pulmonary disease.

2023 Korean Society of Echocardiography position paper for the diagnosis and management of valvular heart disease, part II: mitral and tricuspid valve disease

This manuscript represents the official position of the Korean Society of Echocardiography on valvular heart diseases. This position paper focuses on the diagnosis and management of valvular heart diseases with referring to the guidelines recently published by the American College of Cardiology/American Heart Association and the European Society of Cardiology. The committee sought to reflect national data on the topic of valvular heart diseases published to date through a systematic literature search based on validity and relevance. In the part II of this article, we intend to present recommendations for diagnosis and treatment of mitral valve disease and tricuspid valve disease.

Exercise pulmonary hypertension by the mPAP/CO slope in primary mitral regurgitation

AIMS

Exercise-induced pulmonary hypertension (PH), defined by a mean pulmonary arterial pressure over cardiac output (mPAP/CO) slope >3 mmHg/L/min, has important diagnostic and prognostic implications. The aim of this study is to investigate the value of the mPAP/CO slope in patients with more than moderate primary mitral regurgitation (MR) with preserved ejection fraction and no or discordant symptoms.

METHODS AND RESULTS

A total of 128 consecutive patients were evaluated with exercise echocardiography and cardiopulmonary testing. Clinical outcome was defined as the composite of mitral valve intervention, new-onset atrial fibrillation, cardiovascular hospitalization, and all-cause mortality. The mean age was 63 years, 61% were male, and the mean LVEF was 66 ± 6%. The mPAP/CO slope correlated with peak VO2 (r = -0.52, P < 0.001), while the peak systolic pulmonary artery pressure (sPAP) did not (r = -0.06, P = 0.584). Forty-six per cent (n = 59) had peak exercise sPAP ≥60 mmHg, and 37% (n = 47) had mPAP/CO slope >3 mmHg/L/min. Event-free survival was 55% at 1 year and 46% at 2 years, with reduced survival in patients with mPAP/CO slope >3 mmHg/L/min (hazard ratio, 4.9; 95% confidence interval, 2.9-8.2; P < 0.001). In 53 cases (41%), mPAP/CO slope and peak sPAP were discordant: patients with slope >3 mmHg/L/mmHg and sPAP <60 mmHg (n = 21) had worse outcome vs. peak sPAP ≥60 mmHg and normal slope (n = 32, log-rank P = 0.003). The mPAP/CO slope improved predictive models for outcome, incremental to resting and exercise sPAP, and peak VO2.

CONCLUSION

Exercise PH defined by the mPAP/CO slope >3 mmHg/L/min is associated with decreased exercise capacity and a higher risk of adverse events in significant primary MR and no or discordant symptoms. The slope provides a greater prognostic value than single sPAP measures and peak VO2.

Practice guidance for stress echocardiography

Stress echocardiography has been one of the most promising methods for the diagnosis of ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The Japanese Society of Echocardiography produced practical guidance for the implementation of stress echocardiography in 2018. At that time, stress echocardiography was not yet widely disseminated in Japan; therefore, the 2018 practical guidance for the implementation of stress echocardiography included a report on stress echocardiography and a specific protocol to promote its use at many institutions in Japan in the future. And now, an era of renewed interest and enthusiasm surrounding the diagnosis and treatment of valvular heart disease and heart failure with preserved ejection fraction (HFpEF) has come, which are driven by emerging trans-catheter procedures and new recommended guideline-directed medical therapy. Based on the continued evidence of stress echocardiography, the new practical guideline that describes the safe and effective methodology of stress echocardiography is now created by the Guideline Development Committee of the Japanese Society of Echocardiography and is designed to expand the use of stress echocardiography for valvular heart disease and HFpEF, as well as ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The readers are encouraged to perform stress echocardiography which will enhance the diagnosis and management of these patients.

Left Atrial Stiffness Index as a Predictor of Effort Intolerance and Hemodynamics Evaluated by Invasive Exercise Stress Testing in Degenerative Mitral Regurgitation

In patients with degenerative mitral regurgitation (DMR), peak oxygen consumption is the significant prognostic factor, and exercise intolerance has been considered a trigger for surgical intervention. The significant mitral regurgitation (MR) induces left atrial (LA) remodeling, but the significance of LA stiffness calculated by the ratio of E/e' to LA reservoir strain in degenerative MR has not been elucidated. A total of 30 patients with asymptomatic or minimally symptomatic grade ≥III + DMR underwent the cardiopulmonary exercising test simultaneously with invasive hemodynamic assessment. LA stiffness index significantly correlated with exercise hemodynamic deterioration, including pulmonary arterial wedge pressure (r = 0.71, p <0.01), systolic pulmonary arterial pressure at peak exercise (r = 0.73, p <0.01), and pulmonary circulatory reserve (mean pulmonary arterial pressure/cardiac output slope, r = 0.45, p = 0.012). Multiple linear regression analysis revealed that the higher LA stiffness index was significantly associated with decreased percent predicted peak oxygen consumption (per 0.1 increase, β -4.0, 95% confidence interval -6.9 to -1.3, p <0.01) independently of MR deterioration during exercise. In conclusion, increased LA stiffness was associated with exercise intolerance through hemodynamic deterioration during exercise in patients with asymptomatic or minimally symptomatic severe DMR.

Clinical and Prognostic Implications of Cardiopulmonary Exercise Stress Echocardiography in Asymptomatic Degenerative Mitral Regurgitation

The current guidelines recommend intervention in severe degenerative mitral regurgitation (MR) in symptomatic patients or asymptomatic patients with left ventricular dilatation or dysfunction. The insidious onset of symptoms may mean that patients do not report their symptoms. The role of systematic exercise testing for symptoms in MR is not clearly defined. A total of 97 patients with moderate to severe asymptomatic MR underwent exercise echocardiography combined with cardiopulmonary exercise testing. The predictors of exercise-induced dyspnea, symptom-free survival, and mitral valve intervention were identified. A total of 18 patients (19%) developed limiting dyspnea on exercise. Spontaneous symptom-free survival at 24 months was significantly higher in those without exercise-induced symptoms than those with exercise-induced symptoms, p <0.0001. The only independent predictors of spontaneous symptoms at 2 years were effective regurgitant orifice area (odds ratio 27.45, 95% confidence interval [CI] 1.43 to 528.40, p = 0.03) and exercise-induced symptoms (odds ratio 11.56, 95% CI 1.71 to 78.09, p = 0.01). The only independent predictor of surgery was indexed left ventricular systolic volumes (odds ratio 1.17, 95% CI 1.04 to 1.30, p = 0.006). Where only the patients who underwent surgery due to symptoms were included, the only independent predictor was exercise-induced symptoms (odds ratio 13.94, 95% CI 1.39 to 140.27, p = 0.025). In conclusion, in patients with primary asymptomatic degenerative MR, 1/5 develop revealed symptoms during exercise. This predicts a subsequent development of spontaneous symptoms and mitral valve intervention due to symptoms.

The Global Burden of Valvular Heart Disease: From Clinical Epidemiology to Management

Valvular heart disease is a leading cause of cardiovascular morbidity and mortality and a major contributor of symptoms and functional disability. Knowledge of valvular heart disease epidemiology and a deep comprehension of the geographical and temporal trends are crucial for clinical advances and the formulation of effective health policy for primary and secondary prevention. This review mainly focuses on the epidemiology of primary (organic, related to the valve itself) valvular disease and its management, especially emphasizing the importance of heart valve centers in ensuring the best care of patients through a multidisciplinary team.

Mitral valve transcatheter edge-to-edge repair

Mitral regurgitation (MR) is the most prevalent valvular heart disease and, when left untreated, results in reduced quality of life, heart failure, and increased mortality. Mitral valve transcatheter edge-to-edge repair (M-TEER) has matured considerably as a non-surgical treatment option since its commercial introduction in Europe in 2008. As a result of major device and interventional improvements, as well as the accumulation of experience by the interventional cardiologists, M-TEER has emerged as an important therapeutic strategy for patients with severe and symptomatic MR in the current European and American guidelines. Herein, we provide a comprehensive up-do-date overview of M-TEER. We define preprocedural patient evaluation and highlight key aspects for decision-making. We describe the currently available M-TEER systems and summarise the evidence for M-TEER in both primary mitral regurgitation (PMR) and secondary mitral regurgitation (SMR). In addition, we provide recommendations for device selection, intraprocedural imaging and guiding, M-TEER optimisation and management of recurrent MR. Finally, we provide information on major unsolved questions and "grey areas" in M-TEER.

The prognostic value of exercise-induced pulmonary hypertension in asymptomatic patients with primary mitral regurgitation

BACKGROUND

We examined whether the early development of exercise-induced pulmonary hypertension (EIPH) and right ventricular dysfunction during exercise stress echocardiography (ESE) may predict clinical deterioration in so-called "asymptomatic" patients with primary, at least moderate mitral regurgitation (MR).

METHODS

79 consecutive patients underwent a symptom-limited, graded ESE protocol on semi-supine bicycle at the beginning of the study. During the test, we assessed symptom development, test duration, and the following echocardiographic parameters: MR severity, maximum velocity of the tricuspid regurgitation jet (TR Vmax), pulmonary artery systolic pressure (PASP), and tricuspid annulus systolic excursion (TAPSE). All patients were then followed-up for at least 12 months for clinical end-points (heart failure-related symptoms requiring pharmaceutical therapy, heart failure hospitalization, and/or mitral valve surgery in case of refractory symptoms).

RESULTS

After 16 ± 4 months of follow-up, 75 patients completed the study; 26 of them achieved any clinical end-point and were classified as 'high-risk', while the rest (49 patients) were assigned to the 'low-risk' group. High-risk group showed significantly higher exercise-induced TR Vmax and PASP levels at maximum workload of ESE than low-risk counterparts (p<0.001). Based on receiver operating characteristic analysis, the early (within the first two stages of ESE or up to 50 W) steep rise of calculated PASP ≥51 mmHg (TR Vmax ≥3.4 m/s) had a 92.3% sensitivity and 100% specificity to predict clinical deterioration within the following year. That cut-off value seemed superior predictor than peak value of PASP at the end of ESE. TAPSE levels during ESE did not add prognostic value in our sample.

CONCLUSION

This is the first study demonstrating that the early development of EIPH has prognostic value in asymptomatic patients with primary at least moderate MR and may become a new valid determinant of mitral valve surgery. Additional larger prospective studies are needed to validate our findings.

Prognostic Value of Modified Haller Index in Patients with Suspected Coronary Artery Disease Referred for Exercise Stress Echocardiography

Background:

The influence of chest conformation on outcome of patients with suspected coronary artery disease (CAD) is actually unknown.

Materials and Methods:

This retrospective study included all consecutive patients who underwent exercise stress echocardiography (ESE) for suspected CAD at our institution between February 2011 and September 2019. Modified Haller index (MHI; chest transverse diameter over the distance between sternum and spine) was assessed in all patients. Obstructive CAD was diagnosed by ≥70% stenosis in any epicardial coronary artery. During the follow-up time, we evaluated the occurrence of any of the following: (1) cardiovascular (CV) hospitalizations and (2) cardiac death or sudden death.

Results:

A total of 1091 consecutive patients (62.4 ± 12.6 years, 57.2% of men) were included in the study. Patients with normal chest shape (MHI ≤2.5) and those with concave-shaped chest wall (MHI >2.5) were separately analyzed. A positive ESE was diagnosed in 171 patients of which 80.7% had an obstructive CAD (true positive), while 19.3 not (false positive [FP]). Majority of FP ESE (70.9%) derived from concave-shaped chest wall group. During follow-up time (2.5 ± 1.9 years), 9 patients died and 281 were hospitalized because of heart failure (163), acute coronary syndromes (39), and arrhythmias (79). At the multivariate Cox regression analysis, age (heart rate [HR]: 1.02, 95% confidence interval [CI]: 1.01–1.03), MHI >2.5 (HR: 0.39, 95% CI: 0.26–0.56), diabetes mellitus (HR: 4.89, 95% CI: 3.78–6.32), horizontal ST depression ≥1 mm (HR: 2.86, 95% CI: 1.98–4.15), peak exercise average E/e' ratio (HR: 1.08, 95% CI: 1.06–1.10), and peak exercise wall motion score index (HR: 1.79, 95% CI: 1.36–2.35) were independently correlated with outcome.

Conclusions:

Patients with concave-shaped chest wall (MHI >2.5) have a significantly lower probability of CV events than those with normal chest shape (MHI ≤2.5) over a medium-term follow-up. A noninvasive chest shape assessment could identify subjects at lower risk of CV events.

Updated knowledge and practical implementations of stress echocardiography in ischemic and non-ischemic cardiac diseases: an expert consensus of the Working Group of Echocardiography of the Hellenic Society of Cardiology

Stress echocardiography (SE) is a well-established and valid technique, widely-used for the diagnostic evaluation of patients with ischemic and non-ischemic cardiac diseases. This statement of the Echocardiography Working Group of the Hellenic Society of Cardiology summarizes the consensus of the writing group regarding the applications of SE, based on the expertise of their members and on a critical review of current medical literature. The main objectives of the consensus document include a comprehensive review of SE methodology and training, focusing on the preparation, the protocols used and the analysis of the SE images and an updated, evidence-based knowledge about SE applications on ischemic and non-ischemic heart diseases, such as in cardiomyopathies, heart failure and valvular heart disease.

Determinants of Exercise-Induced Mitral Regurgitation Using Three-Dimensional Transesophageal Echocardiography Combined With Isometric Handgrip Exercise

Using three-dimensional (3D) transesophageal echocardiography (TEE) and isometric handgrip exercise (IHE), we investigated the determinants of exercise-induced mitral regurgitation (MR) according to MR etiologies. Seventy-six patients with more than moderate MR, 40 patients with functional MR (FMR) and 36 patients with degenerative MR (DMR), underwent 3D TEE combined with IHE. Mitral valve (MV) geometry and 3D vena contracta area (3D VCA) were simultaneously evaluated at baseline and during IHE. With regard to exercise-induced MR, Δ3D VCA was calculated as the difference between 3D VCA at baseline and 3D VCA during IHE. IHE caused different changes in MV geometry between etiologies and led to exacerbation of 3D VCA at baseline. Larger Δ3D VCA was observed in the FMR group compared with the DMR group (15.9 ± 10.3 mm² versus 7.3 ± 4.2 mm²; p < 0.0001). In multivariate analyses, tenting height and 3D VCA were selected as independent factors associated with Δ3D VCA in the FMR group (p = 0.0135 and p = 0.0201, respectively), while flail width was selected as an independent factor associated with Δ3D VCA in the DMR group (p = 0.0066). In conclusion, IHE alters mitral valve geometry and causes exacerbation of MR regardless of MR etiology and the determinants of exercise-induced MR differed between MR etiologies.

Appropriate use criteria implementation with modified Haller index for predicting stress echocardiographic results and outcome in a population of patients with suspected coronary artery disease

The hypothesis that modified Haller index (MHI) integration with the existing appropriate use criteria (AUC) categories may predict exercise stress echocardiography (ESE) results and outcome of patients with suspected coronary artery disease (CAD) has never been previously investigated. We retrospectively analyzed 1230 consecutive patients (64.8 ± 13.1 years, 58.9% men) who underwent ESE for suspected CAD between February 2011 and September 2019 at our institution. MHI (chest transverse diameter over the distance between sternum and spine) was assessed in all patients. A true positive (TP) ESE was a positive ESE with obstructive CAD according to subsequent coronary angiography. During follow-up time, we evaluated the occurrence of any of the following: (1) cardiovascular (CV) hospitalizations; (2) Cardiac death or sudden death. Overall, 734 (59.7%), 357 (29.0%) and 139 (11.3%) indications for ESE were classified as appropriate (Group 1), rarely appropriate (Group 2) and which may be appropriate (Group 3), respectively. A funnel chest (defined by an MHI > 2.5) was detected in 30.3%, 82.1% and 49.6% of Groups 1, 2 and 3 subjects, respectively (p < 0.0001). On multivariate logistic regression analysis, male sex (OR 1.41, 95%CI 1.02-2.03, p = 0.01) and type-2 diabetes (OR 3.63, 95%CI 2.49-5.55, p = 0.001) were directly correlated to a TP ESE, while "rarely appropriate" indication for ESE with MHI > 2.5 (OR 0.16, 95%CI 0.11-0.22, p < 0.0001) showed a significant inverse correlation with the outcome. During a mean follow-up of 2.5 ± 1.9 years, 299 CV events occurred: 76.4%, 3.5% and 20.1% in Groups 1, 2 and 3, respectively. On multivariate Cox regression analysis, smoking (HR 1.33, 95%CI 1.19-1.48), type 2 diabetes (HR 2.28, 95%CI 1.74-2.97), dyslipidemia (HR 3.51, 95%CI 2.33-5.15), beta-blockers (HR 0.55, 95%CI 0.41-0.75), statins (HR 0.60, 95%CI 0.45-0.80), peak exercise average E/e' ratio (HR 1.08, 95%CI 1.06-1.09), positive ESE (HR 3.12, 95%CI 2.43-4.01) and finally "rarely appropriate" indication for ESE with MHI > 2.5 (HR 0.15, 95%CI 0.08-0.23) were independently associated with CV events. The implementation of AUC categories with MHI assessment may select a group of patients with extremely low probability of both TP ESE and adverse CV events over a medium-term follow-up. A simple noninvasive chest shape assessment could reduce unnecessary exams.

Cardiopulmonary exercise testing - refining the clinical perspective by combining assessments

INTRODUCTION

Cardiorespiratory fitness (CRF) is now established as a vital sign. Cardiopulmonary exercise testing (CPX) is the gold-standard approach to assessing CRF.

AREAS COVERED

A body of literature spanning several decades clearly supports the clinical utility of CPX in those who are apparently health and at risk for chronic disease as well as numerous patient populations. While CPX, in and of itself, is a valid and reliable clinical assessment, combining findings with other available assessments may provide a more comprehensive perspective that enhances clinical decision making and outcomes. The current review will accomplish the following: (1) define key CPX measures based upon current evidence; and (2) describe the current evidence addressing the relationships between CPX and echocardiography, serum biomarkers, and cardiovascular magnetic resonance.

EXPERT OPINION

Cardiopulmonary exercise testing provides prognostic and diagnostic information in apparently healthy individuals, those at risk for one or more chronic conditions, as well as numerous patient populations. Moreover, if the goal of an intervention is to improve one or more systems integral to the physiologic response to exercise, CPX should be considered as a central assessment to gauge therapeutic efficacy. To further refine the information obtained from CPX, combining other assessments has demonstrated promise.

Cardiopulmonary exercise testing and echocardiographic exam: an useful interaction

Cardiopulmonary exercise test (CPET) is a functional assessment that helps to detect disorders affecting the system involved in oxygen transport and utilization through the analysis of the gas exchange during exercise. The clinical application of CPET is various, it including training prescription, evaluation of treatment efficacy and outcome prediction in a broad spectrum of conditions. Furthermore, in patients with shortness of breath it provides pivotal information to bring out an accurate differential diagnosis between physical deconditioning, cardiopulmonary disease and muscular diseases. Modern software allows the breath-by-breath analysis of the volume of oxygen intake (VO₂), volume of carbon dioxide output (VCO₂) and expired air (VE). Through this analysis, CPET provides a series of additional parameters (peak VO₂, ventilatory threshold, VE/VCO₂ slope, end-tidal carbon dioxide exhaled) that characterize different patterns, helping in diagnosis process. Limitations to the routine use of CPET are mainly represented from the lack of measurement standardization and limited data from randomized multicentric studies. The integration of CPET with exercise stress echocardiography has been recently introduced in the clinical practice by integrating the diagnostic power offered by both the tools. This combined approach has been demonstrated to be valuable for diagnosing several cardiac diseases, including heart failure with preserved or reduced ejection fraction, cardiomyopathies, pulmonary arterial hypertension, valvular heart disease and coronary artery disease. Future investigations are needed to further promote this intriguing combination in the clinical and research setting.

H2FPEF Score for the Prediction of Exercise Intolerance and Abnormal Hemodynamics in Japanese - Evaluation by Exercise Stress Echocardiography Combined With Cardiopulmonary Exercise Testing

BACKGROUND

Both the H₂FPEF-score and nomogram-score, which consist of simple clinical parameters, can assist in diagnosing "early" heart failure with preserved ejection fraction (HFpEF) and only exertional dyspnea, but their these usefulness in Japanese remains unclear. We sought to investigate the correlation between these scores and exercise response, including the peak oxygen uptake (V̇O₂), the pulmonary artery systolic pressure (PASP), the ratio of early diastolic transmitral flow velocity to early diastolic mitral annular velocity (E/e') and stroke volume (SV) using exercise stress echocardiography (ESE) combined with cardiopulmonary exercise testing (CPET).Methods and Results:In this single-center, retrospective cross-sectional study the H₂FPEF-score and nomogram-score were calculated in a total of 139 patients who underwent ESE combined with CPET. The scores correlated with peak V̇O₂(r=-0.48, r=-0.44), PASP (r=0.23, r=0.29) and SV (r=-0.32, r=-0.19) at peak exercise. The nomogram-score correlated with E/e' (r=0.24). The prevalence of exercise intolerance (percent predicted peak V̇O₂<75% and <50%) increased as the H₂FPEF-score increased and reached 88.9% and 22.2% among the patients with high H₂FPEF-score (6-9 points).

CONCLUSIONS

The H₂FPEF-score may be useful as the initial step to diagnosing 'early' HFpEF. The nomogram-score may be more useful in Japanese because of its more universal association with exercise response than the H₂FPEF-score.