Cardiopulmonary Exercise Testing as a Tool for Diagnosing Pulmonary Hypertension in Patients with Dilated Cardiomyopathy

The Current Role of Cardiopulmonary Exercise Test in the Diagnosis and Management of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease with a poor prognosis if left untreated. Despite remarkable achievements in understanding disease pathophysiology, specific treatments, and therapeutic strategies, we are still far from a definitive cure for the disease, and numerous evidences have underlined the importance of early diagnosis and treatment to improve the prognosis. Cardiopulmonary exercise testing (CPET) is the gold standard for assessing functional capacity and evaluating the pathophysiological mechanisms underlying exercise limitation. As effort dyspnea is the earliest and one of the main clinical manifestations of PAH, CPET has been shown to provide valid support in early detection, differential diagnosis, and prognostic stratification of PAH patients, being a useful tool in both the first approach to patients and follow-up. The purpose of this review is to present the current applications of CPET in pulmonary hypertension and to propose possible future utilization to be further investigated.

Clinical characteristics, etiological profile, treatment and long term outcomes in patients with non ischemic systolic heart failure; Himachal Pradesh Heart failure registry (HP-HF registry)

BACKGROUND

The data on clinical characteristics, treatment practices and out comes in patients with Non- ischemic Systolic Heart Failure (NISHF) is limited. We report clinical characteristics, treatment and outcomes in patients with NISHF.

METHODS

1004 patients with NISHF were prospectively enrolled and their demographics, clinical characteristics, and treatment were recorded systematically. Patients were followed annually for a median of 3 years (1 year to 8 years) for allcause death, major adverse cardiovascular events (MACE); composite of all-cause death, hospitalization of heart failure, and or for stroke.

RESULTS

Patients of NISHF were middle-aged (58.8±16.2 years) population with severely depressed left ventricular ejection fraction (29.3±7.02%) and 31.1% had symptoms of advanced Heart failure. Hypertension (43.6%), obesity and or overweight (28.0%), Diabetes (15.0%), and valvular heart disease (11.8%) were the common risk factors. The guideline directed medical treatment was prescribed in more than 80% of the study cohort. Incidence of all cause death and MACE was 7 (6.8, 8.8) per 100 person years and 11(10, 13) per 100 person years respectively. The cumulative incidence of deaths and MACE was 35% (30%, 40%) and 49% (44%, 53%) at 8 years of follow-up.

CONCLUSIONS

Patients of NISHF were middle-aged population with severely depressed LV systolic function with significant incident morbidity and mortality. Early detection of risk factors and their risk management and enhancing the use of guideline directed treatment may improve the outcomes.

Risk stratification in cardiomyopathy

Prognostic stratification of cardiomyopathies represents a cornerstone for the appropriate management of patients and is focused mainly on arrhythmic events and heart failure. Cardiopulmonary exercise testing provides additional prognostic information, particularly in the setting of heart failure. Cardiopulmonary exercise testing data, integrated in scores such as the Metabolism Exercise Cardiac Kidney Index score have been shown to improve the risk stratification of these patients. Cardiopulmonary exercise testing has been analysed as a potential supplier of prognostic parameters in the context of hypertrophic cardiomyopathy, for which it has been shown that a reduced oxygen consumption peak, an increased ventilation/carbon dioxide production slope and chronotropic incompetence correlate with a worse prognosis. To a lesser extent, in dilated cardiomyopathy, it has been shown that the percentage of oxygen consumption peak, not the pure value, and the ventilation/carbon dioxide production slope are associated with a greater cardiovascular risk. Few data are available about other cardiomyopathies (arrhythmogenic and restrictive). Cardiomyopathy patients should be early and routinely referred to heart failure advanced centres in order to perform a comprehensive risk stratification which should include a cardiopulmonary exercise test, with variables and cut-offs shown to improve their risk stratification.

Relationships between Pulmonary Hypertension Risk, Clinical Profiles, and Outcomes in Dilated Cardiomyopathy

Pulmonary hypertension (PH) in patients with heart failure (HF) contributes to a poorer prognosis. However, in those with dilated cardiomyopathy (DCM), the true prevalence and role of PH is unclear. Therefore, this study aimed to analyze the profile of DCM patients at various levels of PH risk, determined via echocardiography, and its impact on outcomes. The 502 DCM in- and out-patient records were retrospectively analyzed. Information on patient status was gathered after 45.9 ± 31.3 months. Patients were divided into 3 PH-risk groups based on results from echocardiography measurements: low (L, n = 239, 47.6%), intermediate (I, n = 153, 30.5%), and high (H, n = 110, 21.9%). Symptom duration, atrial fibrillation, ventricular tachyarrhythmia, ejection fraction, right atrial area, and moderate or severe mitral regurgitation were found to be independently associated with PH risk. During the follow-up period, 83 (16.5%) DCM patients died: 29 (12.1%) in L, 31 (20.3%) in I, and 23 (20.9%) in H. L-patients had a significantly lower risk of all-cause death (L to H: HR 0.55 (95%CI 0.32–0.98), p = 0.01), while no differences in prognosis were found between I and H. In conclusion, over one in five DCM patients had a high PH risk, and low PH risk was associated with better prognoses.

Diagnostic Validity of Cardiopulmonary Exercise Testing for Screening Pulmonary Hypertension in Patients With Chronic Obstructive Pulmonary Disease

PURPOSE

To determine diagnostic validity of cardiopulmonary exercise testing (CPX) parameters for detecting pulmonary hypertension (PH) in patients with chronic obstructive pulmonary disease (COPD) and to investigate association between CPX parameters and indices of PH.

METHODS

This cross-sectional study enrolled 48 moderate to very severe COPD patients in whom PH was confirmed by echocardiography. Symptom-limited CPX was performed using an incremental exercise protocol. Relevant CPX parameters were derived and were tested for their diagnostic ability for diagnosing PH. Logistic regression was applied to examine the effect of various clinical covariates on the diagnostic ability of exercise test variables for detecting PH.

RESULTS

Of the 48 patients, 29 were diagnosed with PH and 19 were negative for PH based on echocardiographic testing. CPX measures including peak oxygen uptake (% predicted (Equation is included in full-text article.)O2peak, (Equation is included in full-text article.)O2peak [mL/min], (Equation is included in full-text article.)O2/kg), oxygen pulse ((Equation is included in full-text article.)O2/HR % predicted, (Equation is included in full-text article.)O2/HR mL/beat), and peak minute ventilation ((Equation is included in full-text article.)Epeak [L/m]) were inversely correlated with mean pulmonary arterial pressure (mPAP). Peak (Equation is included in full-text article.)O2/HR and (Equation is included in full-text article.)O2peak were found to be significant predictors of PH in univariate analysis. (Equation is included in full-text article.)O2peak (%), (Equation is included in full-text article.)O2/HR (mL/beat), and desaturation (%) were identified as independent predictors of PH adjusted for age, forced expiratory volume in 1 sec (%), and forced vital capacity (L).

CONCLUSION

The present study validates the use of CPX parameters such as (Equation is included in full-text article.)O2peak and (Equation is included in full-text article.)O2/HR as a diagnostic tool for correctly identifying PH in COPD patients. Therefore, CPX may be used as an adjunct to echocardiographic measurement of PH where there is unavailability of equipment and expertise.

Medium-term health-related quality of life in patients with pulmonary arterial hypertension treated with goal-oriented sequential combination therapy based on exercise capacity

Background

Pulmonary arterial hypertension (PAH) remains a life-threatening condition, despite modern therapies. We prospectively investigated the therapeutic health-related quality of life (HRQOL) effects of goal-oriented sequential combination therapy based on exercise capacity in patients newly diagnosed with PAH.

Methods

To examine the changes in HRQOL in PAH patients, we treated 30 patients newly diagnosed with PAH with goal-oriented sequential combination therapy based on exercise capacity. We monitored exercise capacity by cardiopulmonary exercise testing and observed the benefit of using a peak VO₂ cut-off of 15 mL/kg/min to guide combination therapy. First-line treatment was an endothelin receptor antagonist (ERA); second-line treatment was the addition of a phosphodiesterase-5 inhibitor (PDE-5I). At baseline and at 3, 6, and 12 months, HRQOL was evaluated by using the eight-item Medical Outcomes Survey Short Form Health Survey.

Results

At 12 months, 100% of PAH patients were receiving an ERA, and 82% an ERA + PDE-5I. The mean physical component summary (PCS) score was 33.5 at baseline, 41.2 at 3 months, 40.8 at 6 months, and 42.0 at 12 months, and the mean mental component summary (MCS) scores were 45.6, 47.0, 50.0, and 50.1, respectively. PCS score was significantly greater at 3 months than at baseline (P = 0.035). MCS score was comparable at 3 months and at baseline, but was significantly greater at 6 and 12 months than at baseline (P = 0.033, P = 0.028, respectively). Thus, PCS score improved soon after initiation of therapy, and MCS score improved later.

Conclusions

Together, these results suggest that goal-oriented sequential combination therapy based on exercise capacity improves HRQOL in patients with PAH.