A. Chelvanathan

The impact of repeated marathon running on cardiovascular function in the aging population

BackgroundSeveral studies have correlated elevations in cardiac biomarkers of injury post marathon with transient and reversible right ventricular (RV) systolic dysfunction as assessed by both transthoracic echocardiography (TTE) and cardiovascular magnetic resonance (CMR). Whether or not permanent myocardial injury occurs due to repeated marathon running in the aging population remains controversial.ObjectivesTo assess the extent and severity of cardiac dysfunction after the completion of full marathon running in individuals greater than 50 years of age using cardiac biomarkers, TTE, cardiac computed tomography (CCT), and CMR.MethodsA total of 25 healthy volunteers (21 males, 55 ± 4 years old) from the 2010 and 2011 Manitoba Full Marathons (26.2 miles) were included in the study. Cardiac biomarkers and TTE were performed one week prior to the marathon, immediately after completing the race and at one-week follow-up. CMR was performed at baseline and within 24 hours of completion of the marathon, followed by CCT within 3 months of the marathon.ResultsAll participants demonstrated an elevated cTnT post marathon. Right atrial and ventricular volumes increased, while RV systolic function decreased significantly immediately post marathon, returning to baseline values one week later. Of the entire study population, only two individuals demonstrated late gadolinium enhancement of the subendocardium in the anterior wall of the left ventricle, with evidence of stenosis of the left anterior descending artery on CCT.ConclusionsMarathon running in individuals over the age of 50 is associated with a transient, yet reversible increase in cardiac biomarkers and RV systolic dysfunction. The presence of myocardial fibrosis in older marathon athletes is infrequent, but when present, may be due to underlying occult coronary artery disease.

The Role of Tissue Doppler Imaging in Predicting Left Ventricular Filling Pressures in Patients Undergoing Cardiac Surgery: An Intraoperative Study

Introduction: The perioperative management of patients undergoing cardiac surgery usually requires the accurate assessment of left ventricular filling pressures (LVFP). The gold standard for determining LVFP involves the use of pulmonary artery catheters (PAC). Using tissue Doppler indices (TDI) obtained by transthoracic echocardiography, the ratio of early transmitral filling velocity to the corresponding early mitral annular velocity (E/E′) has a strong correlation with pulmonary capillary wedge pressure (PCWP). Little is known, however, on whether this relationship between E/E′ and PCWP is valid intraoperatively using transesophageal echocardiography (TEE) during cardiac surgery. Objective: The objective of our study was to determine whether TDI obtained by intraoperative TEE during cardiac surgery can accurately estimate PCWP using PAC as the gold standard. Methods and Results: A total of 34 patients (26 males, mean age 64 ± 9 years) undergoing cardiac surgery were prospectively enrolled between 2010 and 2011 at a single tertiary care center. Conventional diastolic and tissue Doppler parameters were evaluated using intraoperative TEE with concurrent PAC monitoring before and after cardiopulmonary bypass (CPB) surgery. At both pre‐ and post‐CPB, there was no significant correlation between lateral, septal, and mean E/E′ obtained by TEE and PCWP. Conclusion: Intraoperative TEE was unable to accurately predict LVFP in patients undergoing cardiac surgery. PAC may continue to be the gold standard in the assessment of LVFP for this patient population.

Renal Insufficiency and Early Bystander CPR Predict In-Hospital Outcomes in Cardiac Arrest Patients Undergoing Mild Therapeutic Hypothermia and Cardiac Catheterization: Return of Spontaneous Circulation, Cooling, and Catheterization Registry (ROSCCC Registry).

Objective. Out of hospital cardiac arrest (OHCA) patients are a critically ill patient population with high mortality. Combining mild therapeutic hypothermia (MTH) with early coronary intervention may improve outcomes in this population. The aim of this study was to evaluate predictors of mortality in OHCA patients undergoing MTH with and without cardiac catheterization. Design. A retrospective cohort of OHCA patients who underwent MTH with catheterization (MTH + C) and without catheterization (MTH + NC) between 2006 and 2011 was analyzed at a single tertiary care centre. Predictors of in-hospital mortality and neurologic outcome were determined. Results. The study population included 176 patients who underwent MTH for OHCA. A total of 66 patients underwent cardiac catheterization (MTH + C) and 110 patients did not undergo cardiac catheterization (MTH + NC). Immediate bystander CPR occurred in approximately half of the total population. In the MTH + C and MTH + NC groups, the in-hospital mortality was 48% and 78%, respectively. The only independent predictor of in-hospital mortality for patients with MTH + C, after multivariate analysis, was baseline renal insufficiency (OR = 8.2, 95% CI 1.8–47.1, and p = 0.009). Conclusion. Despite early cardiac catheterization, renal insufficiency and the absence of immediate CPR are potent predictors of death and poor neurologic outcome in patients with OHCA.

Can long-term ventricular assist devices be safely implanted in low-volume, non-heart transplant centres?

BACKGROUND Mechanical circulatory support (MCS) using long-term ventricular assist devices (VADs) is an established therapy in select patients with advanced heart failure. Studies have suggested that outcomes after VAD implantation may be dependent on institutional procedural volume, and outcome data from non-transplant centres are lacking. This study reviews the outcomes of patients who received a long-term VAD at our centre to determine if these devices can be safely implanted at tertiary care, low-volume, non-transplant centres. METHODS We conducted a single-centre retrospective cohort study, examining the clinical outcomes of consecutive patients who received a long-term VAD over a 42-month period. RESULTS During the study period 73 patients required MCS, of whom 16 received a long-term VAD. This select group had a mean Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile of 1.6 (0.9) and before implantation 94% required at least 1 inotropic medication, 69% had suffered a cardiac arrest, 63% required an intra-aortic balloon pump, 69% required mechanical ventilation, and 44% required short-term MCS. The primary outcome of survival to transplant or ongoing MCS at 1 year was achieved in 75% of patients. Operating room, intensive care unit, and hospital survival were 100%, 88%, and 81%, respectively. CONCLUSIONS Long-term VADs can be implanted at low-volume, nontransplant centres with survival rates comparable with contemporary clinical trials. Availability of a specialty trained multidisciplinary team with expertise in short-term and long-term MCS options facilitates appropriate patient selection and might be more important than institutional volume in determining outcomes after implantation.