Ronald K. Binder

Methodological approach to the first and second lactate threshold in incremental cardiopulmonary exercise testing

Determination of an ‘anaerobic threshold’ plays an important role in the appreciation of an incremental cardiopulmonary exercise test and describes prominent changes of blood lactate accumulation with increasing workload. Two lactate thresholds are discerned during cardiopulmonary exercise testing and used for physical fitness estimation or training prescription. A multitude of different terms are, however, found in the literature describing the two thresholds. Furthermore, the term ‘anaerobic threshold’ is synonymously used for both, the ‘first’ and the ‘second’ lactate threshold, bearing a great potential of confusion. The aim of this review is therefore to order terms, present threshold concepts, and describe methods for lactate threshold determination using a three-phase model with reference to the historical and physiological background to facilitate the practical application of the term ‘anaerobic threshold’.

Clinical ResearchInterventional CardiologyTranscatheter Aortic Valve Replacement With the St. Jude Medical Portico Valve: First-in-Human Experience

OBJECTIVES The purpose of this study was to demonstrate the feasibility and procedural outcomes with a new self-expanding and repositionable transcatheter heart valve. BACKGROUND Transcatheter aortic valve replacement is a viable option for selected patients with severe symptomatic aortic stenosis. However, suboptimal prosthesis positioning may contribute to paravalvular regurgitation, atrioventricular conduction block, and mitral or coronary compromise. METHODS The repositionable Portico valve (St. Jude Medical, Minneapolis, Minnesota) was implanted in 10 patients with severe aortic stenosis utilizing percutaneous femoral arterial access. Patients underwent transthoracic and transesophageal echocardiography and multidetector computed tomography before and after valve implantation. Clinical and echocardiographic follow-up was obtained at 30 days. RESULTS Device implantation was successful in all patients. Prosthesis recapture and repositioning was performed in 4 patients. Intermittent prosthetic leaflet dysfunction in 1 patient required implantation of a second transcatheter valve. There was 1 minor stroke. At 30-day follow-up, echocardiographic mean transaortic gradient was reduced from 44.9 ± 16.7 mm Hg to 10.9 ± 3.8 mm Hg (p < 0.001), and valve area increased from 0.6 ± 0.1 cm(2) to 1.3 ± 0.2 cm(2) (p < 0.001). Paravalvular regurgitation was mild or less in 9 patients (90%) and moderate in 1 patient (10%). There were no major strokes, major vascular complications, major bleeds, or deaths. No patient required pacemaker implantation. All patients were in New York Heart Association functional class II or less. CONCLUSIONS Transcatheter aortic valve replacement with the repositionable Portico transcatheter heart valve is feasible, with good short-term clinical and hemodynamic outcomes.

Prediction of Optimal Deployment Projection for Transcatheter Aortic Valve Replacement Angiographic 3-Dimensional Reconstruction of the Aortic Root Versus Multidetector Computed Tomography

Background— Identifying the optimal fluoroscopic projection of the aortic valve is important for successful transcatheter aortic valve replacement (TAVR). Various imaging modalities, including multidetector computed tomography (MDCT), have been proposed for prediction of the optimal deployment projection. We evaluated a method that provides 3-dimensional angiographic reconstructions (3DA) of the aortic root for prediction of the optimal deployment angle and compared it with MDCT. Methods and Results— Forty patients undergoing transfemoral TAVR at St Pauls Hospital, Vancouver, Canada, were evaluated. All underwent preimplant 3DA and 68% underwent preimplant MDCT. Three-dimensional angiographic reconstructions were generated from images of a C-arm rotational aortic root angiogram during breath-hold, rapid ventricular pacing, and injection of 32 mL contrast medium at 8 mL/s. Two independent operators prospectively predicted perpendicular valve projections. The implant angle was chosen at the discretion of the physician performing TAVR. The angles from 3DA, from MDCT, the implant angle, and the postdeployment perpendicular prosthesis view were compared. The shortest distance from the postdeployment perpendicular prosthesis projection to the regression line of predicted perpendicular projections was calculated. All but 1 patient had adequate image quality for reproducible angle predictions. There was a significant correlation between 3DA and MDCT for prediction of perpendicular valve projections (r=0.682, P<0.001). Deviation from the regression line of predicted angles to the postdeployment prosthesis view was 5.1±4.6° for 3DA and 7.9±4.9° for MDCT (P=0.01). Conclusions— Three-dimensional angiographic reconstructions and MDCT are safe, practical, and accurate imaging modalities for identifying the optimal perpendicular valve deployment projection during TAVR.

Impact of low-profile sheaths on vascular complications during transfemoral transcatheter aortic valve replacement.

AIMS We sought to assess the impact of low-profile sheaths on vascular complications during transfemoral transcatheter aortic valve replacement (TAVR). METHODS AND RESULTS This retrospective single-study population comprised a total of 375 consecutive patients with severe aortic stenosis who underwent transfemoral TAVR from January 2008 to November 2012. Of these, 204 (54.4%) underwent TAVR using 14-18 Fr sheaths (low-profile sheath [LPS] group), and 171 (45.6%) using 19-24 Fr sheaths (high-profile sheath [HPS] group). Vascular complications and bleeding were defined according to the VARC-2 definitions. Lower-profile sheaths were associated with a lower incidence of major vascular complications (0.5% vs. 10.5%, p<0.001), as well as a lower rate of life-threatening or major bleeding (3.4% vs. 8.3%, p=0.038). Finally, at multivariable analysis, sheath size ≥19 Fr (adjusted odds ratio [OR]: 3.06, 95% confidence interval [CI]: 1.20-7.83; p=0.019) and a sheath external diameter/minimal femoral artery diameter ratio ≥1.05 (adjusted OR: 5.79, 95% CI: 1.29-15.92, p=0.022) were found to be the only independent predictors of major and minor vascular complications. CONCLUSIONS The introduction of lower-profile sheaths has dramatically reduced the incidence of vascular complications after transfemoral TAVR, thus enhancing the safety of the procedure.

Edwards SAPIEN 3 valve.

Building on the established success with the SAPIEN, SAPIEN XT and earlier prototypic transcatheter heart valves (THV) the newest balloon-expandable valve incorporates a number of new and enhanced features intended to reduce the risk of vascular injury, to reduce paravalvular regurgitation, and to facilitate rapid and accurate positioning and implantation. The SAPIEN 3 THV incorporates a cobalt chromium stent, bovine pericardial leaflets, and both an inner and new outer polyethylene terephthalate sealing cuff. The delivery system incorporates an active three-dimensional coaxial positioning catheter, and is compatible with a 14 Fr expandable sheath.

Exercise training reverses exertional oscillatory ventilation in heart failure patients

Exertional oscillatory ventilation (EOV) is an ominous prognostic sign in chronic heart failure (CHF), but little is known about the success of specific therapeutic interventions. Our aim was to study the impact of an exercise training on exercise capacity and cardiopulmonary adaptation in stable CHF patients with left ventricular systolic dysfunction and EOV. 96 stable CHF patients with EOV were included in a retrospective analysis (52 training versus 44 controls). EOV was defined as follows: 1) three or more oscillatory fluctuations in minute ventilation (V′E) during exercise; 2) regular oscillations; and 3) minimal average ventilation amplitude ≥5 L. EOV disappeared in 37 (71.2%) out of 52 patients after training, but only in one (2.3%) out of 44 without training (p<0.001). The decrease of EOV amplitude correlated with changes in end-tidal carbon dioxide tension (r= -0.60, p<0.001) at the respiratory compensation point and V′E/carbon dioxide production (V′CO2) slope (r=0.50, p<0.001). Training significantly improved resting values of respiratory frequency (fR), V′E, tidal volume (VT) and V′E/V′CO2 ratio. During exercise, V′E and VT reached significantly higher values at the peak, while fR and V′E/V′CO2 ratio were significantly lower at submaximal exercise. No change was noted in the control group. Exercise training leads to a significant decrease of EOV and improves ventilatory efficiency in patients with stable CHF.

The Impact of Anemia on Long-Term Clinical Outcome in Patients Undergoing Revascularization With the Unrestricted Use of Drug-Eluting Stents

Background— Anemia is frequent among patients with cardiovascular disease and adversely affects prognosis. The objective of this analysis was to assess the impact of anemia on long-term clinical outcomes among patients undergoing percutaneous coronary intervention (PCI) with the unrestricted use of drug-eluting stents (DES). Methods and Results— Between April 2002 to March 2009, 6528 consecutive patients underwent PCI with the unrestricted use of DES. Among patients with anemia according to the criteria by the World Health Organization (WHO) (hemoglobin <130 g/L for men and <120 g/L for women, respectively) patients below the 25th percentile separately for men and women were defined to have severe anemia. We compared clinical outcomes among patients with severe anemia and no/mild anemia during long-term follow-up through 4 years. Whereas 21.6% of patients were found to have anemia according to the WHO definition, 347 patients (5.5%) had severe anemia (mean hemoglobin, 98±11 g/L). Severe anemia was more prevalent among the elderly (P<0.001), diabetics (P<0.001), and patients with chronic kidney disease (P<0.001). In adjusted analyses, severe anemia was associated with an increased risk of death (hazard ratio, 1.86; 95% confidence interval, 1.37–2.52; P<0.0001), cardiac death (hazard ratio, 2.32; 95% confidence interval, 1.57–3.43; P<0.0001), and myocardial infarction (hazard ratio, 2.02; 95% confidence interval, 1.36–3.01; P=0.00054) as compared with no/mild anemia without significant interaction across sexes (P=0.86) and acute coronary syndromes (P=0.61) and a trend toward a particularly high risk of mortality among anemic patients <65 years of age (P=0.07). Severe anemia resulted in a greater risk of overall definite stent thrombosis (hazard ratio, 2.59; 95% confidence interval, 1.48–4.54; P=0.00089). Conclusions— Severe anemia is common among patients undergoing PCI with the unrestricted use of DES and adversely affects long-term prognosis, including survival.

Haemodynamic and arrhythmic effects of moderately cold (22°C) water immersion and swimming in patients with stable coronary artery disease and heart failure

Data on moderately cold water immersion and occurrence of arrhythmias in chronic heart failure (CHF) patients are scarce.

“One-Stop Shop”: Safety of Combining Transcatheter Aortic Valve Replacement and Left Atrial Appendage Occlusion

OBJECTIVES The aim of this study was to investigate the safety and efficacy of combining transcatheter valve replacement (TAVR) and left atrial appendage occlusion (LAAO) versus TAVR alone. BACKGROUND Patients with severe aortic stenosis and atrial fibrillation undergoing TAVR are at increased risk for stroke and bleeding complications. METHODS A cohort of 52 patients undergoing concomitant TAVR and LAAO were compared with 52 patients undergoing isolated TAVR. A primary safety endpoint at 30 days, a clinical efficacy endpoint from day 30 to last follow-up, and an LAAO efficacy endpoint from the first post-interventional day to the last follow-up were chosen. RESULTS The mean age of the study population was 85 ± 5 years. The mean CHA2DS2-VASc score and HAS-BLED score were 3.9 ± 1.1 and 2.6 ± 0.9, respectively. The mean Society of Thoracic Surgeons score was 7.8 ± 5.5. The median follow-up duration of the study population was 9.4 months (range 0 to 48 months). The primary safety endpoint occurred in 10 patients in the concomitant group and in 7 patients in the isolated TAVR group (19% vs. 14%; 95% confidence interval: 0.59 to 4.06). The clinical and LAAO efficacy endpoints were achieved in 81 (79%) (75% vs. 82%; 95% confidence interval: 0.49 to 2.92) and 75 (73%) patients (69% vs. 76%; 95% confidence interval: 0.54 to 2.51), respectively. CONCLUSIONS This pilot study shows that concomitant TAVR and LAAO is feasible and seems to be safe among patients with severe aortic stenosis and atrial fibrillation. Larger trials and longer follow-up are needed to confirm the safety and efficacy of such an approach.

Transcatheter aortic-valve implantation with one single minimal contrast media injection

Performing transcatheter aortic valve implantation (TAVI) with the use of minimal contrast in patients at high‐risk for acute kidney injury (AKI). Background: Contrast‐induced nephropathy (CIN) is a major cause of AKI following TAVI and is associated with increased morbidity and mortality. The amount of contrast media used increases the risk for CIN.