Background: There is significant evidence that reactive oxygen species play an important role in endothelial dysfunction, ischemia/reperfusion injury as well as in the pathogenesis of diabetes mellitus (DM). It is also known that vitamins C and E have substantial antioxidant properties. However, clinical evidence concerning this topic is insufficient so far. The aim of the present study was to determine if the administration of vitamins C and E influences the outcome in diabetic patients with acute myocardial infarction (AMI). Methods: Among 800 patients with AMI included in the MIVIT (Myocardial Infarction and Vitamins) study, 122 patients (15%) had confirmed DM. A retrospective analysis of the influence of vitamins C and E on 30-day cardiac mortality in patients with or without DM was performed. Results: There was a significant reduction in 30-day cardiac mortality in diabetic patients treated with antioxidant vitamins C and E [5 (8%) vs. 14 (22%); OR 0.32, 95% CI 0.11–0.93; p = 0.036]. Such an effect has not been observed in patients without DM [19 (6%) vs. 19 (6%); OR 0.97, 95% CI 0.51–1.85; p = 0.94]. Conclusion: The results suggest that early administration of antioxidant vitamins C and E in patients with AMI and concomitant DM reduces cardiac mortality.

Cardiopulmonary exercise testing (CPET) is an important diagnostic tool in contemporary clinical practice. This document presents an expert opinion from the Working Group on Cardiac Rehabilitation and Exercise Physiology of the Polish Cardiac Society concerning the indications, performance technique, and interpretation of results for CPET in adult cardiology. CPET is an electrocardiographic exercise test expanded with exercise evaluation of ventilatory and gas exchange parameters. It allows for a global assessment of the exercise performance including the pulmonary, cardiovascular, hematopoietic, neuropsychological, and musculoskeletal systems. It provides a noninvasive dynamic evaluation during exercise and is a reference modality for exercise capacity assessment. Moreover, it allows the measurement of numerous prognostic parameters. It is useful in cardiology, pulmonology, oncology, perioperative assessment, rehabilitation as well as in sports medicine and in the evaluation of healthy people. This test not only helps to diagnose the causes of exercise intolerance but also supports the evaluation of the treatment. New opportunities are offered by combining CPET with imaging such as exercise stress echocardiography. These tests are complementary and synergistic in their diagnostic and prognostic strength.

Background: Chronotropic incompetence in patients taking beta-blockers is associated with poor prognosis; however, its impact on exercise capacity (EC) remains unclear. Methods: We analyzed data from consecutive patients taking beta-blockers referred for cardiopulmonary exercise testing to assess EC. Chronotropic incompetence was defined as chronotropic index (CI) ≤ 62%. Results: Among 140 patients all taking beta-blockers (age 61 ± 9.7 years; 73% males), 64% with heart failure, chronotropic incompetence was present in 80.7%. EC assessed as peak oxygen uptake was lower in the group with chronotropic incompetence, 18.3 ± 5.7 vs. 24.0 ± 5.3 mL/kg/min, p < 0.001. EC correlated positively with CI (β = 0.14, p < 0.001) and male gender (β = 5.12, p < 0.001), and negatively with age (β = −0.17, p < 0.001) and presence of heart failure (β = −3.35, p < 0.001). Beta-blocker dose was not associated with EC. Partial correlation attributable to CI accounted for more than one-third of the variance in EC explained by the model (adjusted R² = 59.8%). Conclusions: In patients taking beta-blockers, presence of chronotropic incompetence was associated with lower EC, regardless of the beta-blocker dose. CI accounted for more than one-third of EC variance explained by our model.

Cardiac rehabilitation (CR) is indicated in all patients after acute myocardial infarction (AMI) to improve prognosis and exercise capacity (EC). Previous studies reported that up to a third of patients did not improve their EC after CR (non-responders). Our aim was to assess the cardiac and peripheral mechanisms of EC improvement after CR using combined exercise echocardiography and cardiopulmonary exercise testing (CPET-SE). The responders included patients with an improved EC assessed as a rise in peak oxygen uptake (VO₂) ≥ 1 mL/kg/min. Peripheral oxygen extraction was calculated as arteriovenous oxygen difference (A-VO₂Diff). Out of 41 patients (67% male, mean age 57.5 ± 10 years) after AMI with left ventricular ejection fraction (LVEF) ≥ 40%, 73% improved their EC. In responders, peak VO₂ improved by 27% from 17.9 ± 5.2 mL/kg/min to 22.7 ± 5.1 mL/kg/min, p < 0.001, while non-responders had a non-significant 5% decrease in peak VO₂. In the responder group, the peak exercise heart rate, early diastolic myocardial velocity at peak exercise, LVEF at rest and at peak exercise, and A-VO₂Diff at peak exercise increased, the minute ventilation to carbon dioxide production slope decreased, but the stroke volume and cardiac index were unchanged after CR. Non-responders had no changes in assessed parameters. EC improvement after CR of patients with preserved LVEF after AMI is associated with an increased heart rate response and better peripheral oxygen extraction during exercise.