Exercise oxygen pulse kinetics in patients with hypertrophic cardiomyopathy

The cardiopulmonary exercise test in the prognostic evaluation of patients with heart failure and cardiomyopathies: the long history of making a one-size-fits-all suit

Cardiopulmonary exercise test (CPET) has become pivotal in the functional evaluation of patients with chronic heart failure (HF), supplying a holistic evaluation both in terms of exercise impairment degree and possible underlying mechanisms. Conversely, there is growing interest in investigating possible multiparametric approaches in order to improve the overall HF risk stratification. In such a context, in 2013, a group of 13 Italian centres skilled in HF management and CPET analysis built the Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score, based on the dynamic assessment of HF patients and on some other instrumental and laboratory parameters. Subsequently, the MECKI score, initially developed on a cohort of 2716 HF patients, has been extensively validated as well as challenged with the other multiparametric scores, achieving optimal results. Meanwhile, the MECKI score research group has grown over time, involving up to now a total of 27 centres with an available database accounting for nearly 8000 HF patients. This exciting joint effort from multiple HF Italian centres allowed to investigate different HF research field in order to deepen the mechanisms underlying HF, to improve the ability to identify patients at the highest risk as well as to analyse particular HF categories. Most recently, some of the participants of the MECKI score group started to join the forces in investigating a possible additive role of CPET assessment in the cardiomyopathy setting too. The present study tells the ten-year history of the MECKI score presenting the most important results achieved as well as those projects in the pipeline, this exciting journey being far to be concluded.

"Under the Bridge": Looking for Ischemia in a Patient with Intramyocardial Coronary Artery Course-The Role of the Cardiopulmonary Exercise Test

Many variables obtained during cardiopulmonary exercise test (CPET), including O2 uptake (VO2) versus heart rate (HR, O2-pulse) and work rate (VO2/Watt), provide quantitative patterns of responses to exercise when left ventricular dysfunction is an effect of myocardial ischemia (MI). Therefore, CPET offers a unique approach to evaluate exercise-induced MI in the presence of fixed or dynamic coronary arteries stenosis. In this paper, we examined the case of a 74-year-old patient presenting with an ischemic CPET and a normal stress cardiac magnetic resonance (CMR) with dipyridamole. A coronary angiography demonstrated the presence of myocardial bridging (MB), a well-known congenital coronary anomaly that is able to generate MI during exercise (but not in provocative testing using coronary artery vasodilators, such as dipyridamole). Despite the good diagnostic accuracy of the imaging methods (i.e., stress CMR) in MI detection, this case shows that exercise should be the method of choice in elicit ischemia in specific cases, like MB.

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.

Early flattening of the oxygen pulse during the cardiopulmonary exercise test in asymptomatic adults and its association with cardiovascular risk factors

BACKGROUND

Individuals with cardiovascular exercise limitations present oxygen pulse morphology with early flattening (plateau) during the cardiopulmonary exercise test (CPET). Although this oxygen pulse response is well known in cardiac patients, these changes' prevalence and clinical relevance in asymptomatic individuals are not known. We aimed to quantify the proportion of asymptomatic adults with an early flattening of the oxygen pulse and investigate its association with classical cardiovascular risk factors.

METHODS

We carried out a cross-sectional study with a sample of 824 adults aged between 18 and 80 years. We assessed anthropometry, body composition, and cardiovascular risk. In addition, we obtained cardiorespiratory and metabolic responses during a ramp protocol treadmill CPET.

RESULTS

The prevalence of early flattening of the oxygen pulse was 36.8%. These participants were predominantly females, older, less educated, with a higher body mass and percentage of fat and a lower percentage of lean body mass. After a multinominal multiple logistic regression analysis, we identified female sex (odds ratio, 5.46: 95% confidence interval, 3.73-7.99), low education (2.24: 1.47-3.42), dyslipidemia (1.67: 1.14-2.45), smoking (1.64: 1.00-2.69), and physical inactivity (1.39: 1.02-1.96) as the leading independent predictors of the early flattening of oxygen pulse.

CONCLUSION

The early flattening of oxygen pulse is common in asymptomatic adults and is highly determined by modifiable cardiovascular risk factors. These results suggest that identifying the early flattening of oxygen pulse may be helpful in the prevention of cardiovascular diseases.