A Strategy of Underexpansion and Ad Hoc Post-Dilation of Balloon-Expandable Transcatheter Aortic Valves in Patients at Risk of Annular Injury Favorable Mid-Term Outcomes

AbstractObjectivesThe aim of this study was to evaluate a strategy of intentional underexpansion of excessively oversized balloon-expandable transcatheter heart valves (THVs) in terms of clinical outcomes, valve function, and frame durability at 1 year.BackgroundTranscatheter aortic valve replacement requires the selection of an optimally sized THV to ensure paravalvular sealing and fixation without risking annular injury. However, some patients have “borderline” annular dimensions that require choosing between a THV that may be too small or another that may be too large.MethodsWe evaluated 47 patients at risk of annular injury who underwent transcatheter aortic valve replacement (TAVR) with an oversized, but deliberately underexpanded, THV followed by post-dilation if required. Clinical evaluation, echocardiography, and cardiac computed tomography were performed pre-TAVR, post-TAVR, and at 1 year.ResultsDeployment of oversized THVs with modest underfilling of the deployment balloon (<10% by volume) was not associated with significant annular injury. Paravalvular regurgitation was mild or less in 95.7% of patients, with post-dilation required in 10.7%. THV hemodynamic function was excellent and remained stable at 1 year. Computed tomography documented stent frame circularity in 87.5%. Underexpansion was greatest within the intra-annular THV inflow (stent frame area 85.8% of nominal). There was no evidence of stent frame recoil, deformation, or fracture at 1 year.ConclusionsIn carefully selected patients with borderline annulus dimensions and in whom excessive oversizing of a balloon-expandable SAPIEN XT valve (Edwards Lifesciences, Inc., Irvine, California) is a concern, a strategy of deliberate underexpansion, with ad hoc post-dilation, if necessary, may reduce the risk of annular injury without compromising valve performance

Regional Systems of Care to Optimize Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement

AbstractObjectivesThis study sought to describe the development of a multicenter, transcatheter aortic valve replacement program and regional systems of care intended to optimize coordinated, efficient, and appropriate delivery of this new therapy.BackgroundTranscatheter aortic valve replacement (TAVR) has become an accepted treatment option for patients with severe aortic stenosis who are at high surgical risk. Regional systems of care have led to improvements in outcomes for patients undergoing intervention for myocardial infarction, cardiac arrest, and stroke. We implemented a regional system of care for patients undergoing TAVR in British Columbia, Canada.MethodsWe describe a prospective observational cohort of 583 patients who underwent TAVR in British Columbia between 2012 and 2014. Regionalization of TAVR care in British Columbia refers to a centrally coordinated, funded, and evaluated program led by a medical director and a multidisciplinary advisory group that oversees planning, access to care, and quality of outcomes at the 4 provincial sites. Risk-stratified case selection for transfemoral TAVR is performed by heart teams at each site on the basis of consensus provincial indications. Referrals for lower volume and more complicated TAVR, including nontransfemoral access and valve-in-valve procedures, are concentrated at a single site. In-hospital and 30-day outcomes are reported.ResultsThe median age was 83 years (interquartile range [IQR]: 78 to 87 years) and median STS score was 6% (IQR: 4% to 8%). Transfemoral access was performed in 499 (85.6%) cases and nontransfemoral in 84 (14.4%). Transcatheter valve-in-valve procedures in for failed bioprosthetic valves were performed in 43 patients (7.4%). A balloon-expandable valve was inserted in 386 (66.2%) and a self-expanding valve in 189 (32.4%). All-cause 30-day mortality was 3.5%. All-cause in-hospital mortality and disabling stroke occurred in 3.1% and 1.9%, respectively. Median length of stay was 3 days (IQR: 3 to 6 days), with 92.8% of patients discharged directly home.ConclusionsThis experience demonstrates the potential benefits of a regional system of care for TAVR. Excellent outcomes were demonstrated: most patients had short in-hospital stays and were discharged directly home

Improving prognosis in out-of-hospital cardiac arrest through cardiac support and optimization of post-resuscitative care

Out-of-hospital cardiac arrest (OHCA) is a common lethal health problem. Despite significant advances in the diagnosis and treatment of cardiovascular disease, OHCA continues to be a major challenge with unacceptably high mortality and morbidity. Although most research into OHCA has focused on improving rates of return of circulation, many patients die in the post resuscitative period from a unique set of physiological insults, collectively termed the post cardiac arrest syndrome. Over the last decade several clinical trials have highlighted the importance of post-resuscitative care in optimizing survival and neurological recovery. Recently, there have been significant advances in management including recommendations related to regional systems of care, application of therapeutic hypothermia and the utilization of investigative procedures including emergent coronary angiography, cardiac support devices and other tools which provide prognostic information. Despite these advances there has been poor uptake of post-resuscitative care guidelines with significant differences in clinical outcomes between regions and institutions. This thesis focuses on post-resuscitative management in Australia, whilst also exploring new systems and models for OHCA patients in an effort to improve clinical outcomes

Improving prognosis in out-of-hospital cardiac arrest through cardiac support and optimization of post-resuscitative care

Out-of-hospital cardiac arrest (OHCA) is a common lethal health problem. Despite significant advances in the diagnosis and treatment of cardiovascular disease, OHCA continues to be a major challenge with unacceptably high mortality and morbidity. Although most research into OHCA has focused on improving rates of return of circulation, many patients die in the post resuscitative period from a unique set of physiological insults, collectively termed the post cardiac arrest syndrome. Over the last decade several clinical trials have highlighted the importance of post-resuscitative care in optimizing survival and neurological recovery. Recently, there have been significant advances in management including recommendations related to regional systems of care, application of therapeutic hypothermia and the utilization of investigative procedures including emergent coronary angiography, cardiac support devices and other tools which provide prognostic information. Despite these advances there has been poor uptake of post-resuscitative care guidelines with significant differences in clinical outcomes between regions and institutions. This thesis focuses on post-resuscitative management in Australia, whilst also exploring new systems and models for OHCA patients in an effort to improve clinical outcomes

State of Shock: Contemporary Vasopressor and Inotrope Use in Cardiogenic Shock

Cardiogenic shock is characterized by tissue hypoxia caused by circulatory failure arising from inadequate cardiac output. In addition to treating the pathologic process causing impaired cardiac function, prompt hemodynamic support is essential to reduce the risk of developing multiorgan dysfunction and to preserve cellular metabolism. Pharmacologic therapy with the use of vasopressors and inotropes is a key component of this treatment strategy, improving perfusion by increasing cardiac output, altering systemic vascular resistance, or both, while allowing time and hemodynamic stability to treat the underlying disease process implicated in the development of cardiogenic shock. Despite the use of mechanical circulatory support recently garnering significant interest, pharmacologic hemodynamic support remains a cornerstone of cardiogenic shock management, with over 90% of patients receiving at least 1 vasoactive agent. This review aims to describe the pharmacology and hemodynamic effects of current pharmacotherapies and provide a practical approach to their use, while highlighting important future research directions

The impact of time to amiodarone administration on survival from out-of-hospital cardiac arrest

Aim: To examine the impact of time to amiodarone administration on survival from shock-refractory Ventricular Fibrillation/pulseless Ventricular Tachycardia (VF/pVT) following out-of-hospital cardiac arrest (OHCA). Methods: A retrospective cohort study of adult (≥16 years) OHCA patients in shock-refractory VF/pVT (after 3 consecutive defibrillation attempts) of medical aetiology who arrested between January 2010 and December 2019. Time-dependent propensity score matching was used to sequentially match patients who received amiodarone at any given minute of resuscitation with patients eligible to receive amiodarone during the same minute. Log-binomial regression models were used to assess the association between time of amiodarone administration (by quartiles of time-to-matching) and survival outcomes. Results: A total of 2,026 patients were included, 1,393 (68.8%) of whom received amiodarone with a median (interquartile range) time to administration of 22.0 (18.0–27.0) minutes. Propensity score matching yielded 1,360 matched pairs. Amiodarone administration within 28 minutes of the emergency call was associated with a higher likelihood of return of spontaneous circulation (ROSC) (≤18minutes: RR = 1.03 (95%CI 1.02, 1.04); 19-22minutes: RR = 1.02 (95%CI 1.01, 1.03); 23-27minutes: RR = 1.01 (95%CI 1.00, 1.02)) and event survival (pulse on hospital arrival) (≤18 minutes: RR = 1.05 (95%CI 1.03, 1.07); 19–22 minutes: RR = 1.03 (95%CI 1.01, 1.05); 23–27 minutes: RR = 1.02 (95%CI 1.00, 1.03). Amiodarone administration within 23 minutes of the emergency call was associated with a higher likelihood of survival to hospital discharge (≤18minutes: RR = 1.17 (95%CI 1.09, 1.24; 19–22 minutes: RR = 1.10 (95%CI 1.04, 1.17). Conclusion: Amiodarone administered within 23 minutes of the emergency call is associated with improved survival outcomes in shock-refractory VF/pVT, although prospective trials are required to confirm these findings

Increasing the Uptake of Cardiopulmonary Resuscitation Training Within Australian Cardiac Rehabilitation Programs

Background: People attending Cardiac Rehabilitation (CRehab) are at increased risk of cardiac arrest. We have demonstrated that people attending CR would like to be taught cardiopulmonary resuscitation (CPR) yet provision of CPR training in Australian CRehab programmes is 24%. Aim: This study aimed to identify the best strategy to implement CPR training into CR programmes. Methods: A two-arm randomised controlled implementation study is being conducted across Australia. One CRehab coordinator per programme are eligible to participate. Coordinators are randomised 1:1 and receive an information pack (control & intervention) and a face-to-face education session (intervention). Results: To date 36 programmes (61% metropolitan, 39% rural) have been randomised. Few programmes had (14%) offered past CPR training and only 17% currently include CPR information. Baseline data identified common barriers to incorporating CPR training were time (69%), resources (69%) and a lack of awareness (19%). Coordinators are motivated to include CPR training as they believe that participants are interested in learning CPR (78%). Of the 12 programmes to complete the study to date, 70% have incorporated CPR training into their programmes (80% intervention, 60% control). Time was the most common barrier (67%) to implementation. Brief qualitative interviews with coordinators revealed that staffing, the responsibility of conducting CPR training and a reluctance to change were additional barriers. Conclusions: CR represents a logical location to provide targeted CPR training to high-risk cardiac groups at scale nationally. This study will aid understanding of how CR coordinators can be supported to enable more programmes to incorporate CPR training

Increasing the Uptake of Cardiopulmonary Resuscitation Training Within Australian Cardiac Rehabilitation Programmes

Background: People attending Cardiac Rehabilitation (CRehab) are at increased risk of cardiac arrest. We have demonstrated that people attending CR would like to be taught cardiopulmonary resuscitation (CPR) yet provision of CPR training in Australian CRehab programmes is 24%.Aim: This study aimed to identify the best strategy to implement CPR training into CR programmes.Methods: A two-arm randomised controlled implementation study is being conducted across Australia. One CRehab coordinator per programme are eligible to participate. Coordinators are randomised 1:1 and receive an information pack (control &amp; intervention) and a face-to-face education session (intervention).Results: To date 36 programmes (61% metropolitan, 39% rural) have been randomised. Few programmes had (14%) offered past CPR training and only 17% currently include CPR information. Baseline data identified common barriers to incorporating CPR training were time (69%), resources (69%) and a lack of awareness (19%). Coordinators are motivated to include CPR training as they believe that participants are interested in learning CPR (78%). Of the 12 programmes to complete the study to date, 70% have incorporated CPR training into their programmes (80% intervention, 60% control). Time was the most common barrier (67%) to implementation. Brief qualitative interviews with coordinators revealed that staffing, the responsibility of conducting CPR training and a reluctance to change were additional barriers.Conclusions: CR represents a logical location to provide targeted CPR training to high-risk cardiac groups at scale nationally. This study will aid understanding of how CR coordinators can be supported to enable more programmes to incorporate CPR training

Effects of supplemental oxygen therapy in patients with suspected acute myocardial infarction: A meta-analysis of randomized clinical trials

BACKGROUND:Although oxygen therapy has been used for over a century in the management of patients with suspected acute myocardial infarction (AMI), recent studies have raised concerns around the efficacy and safety of supplemental oxygen in normoxaemic patients.OBJECTIVE:To synthesise the evidence from randomised controlled trials (RCTs) that investigated the effects of supplemental oxygen therapy compared with room air in patients with suspected or confirmed AMI.METHODS:For this aggregate data meta-analysis, multiple databases were searched from inception to 30 September 2017. RCTs with any length of follow-up and any outcome measure were included if they studied the use of supplemental O2 therapy administered by any device at normal pressure compared with room air. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, an investigator assessed all the included studies and extracted the data. Outcomes of interests included mortality, troponin levels, infarct size, pain and hypoxaemia.RESULTS:Eight RCTs with a total of 7998 participants (3982 and 4002 patients in O2 and air groups, respectively) were identified and pooled. In-hospital and 30-day death occurred in 135 and 149 patients, respectively. Oxygen therapy did not reduce the risk of in-hospital (OR, 1.11 (95% CI 0.69 to 1.77)) or 30-day mortality (OR, 1.09 (95% CI 0.80 to 1.50)) in patients with suspected AMI, and the results remained similar in the subgroup of patients with confirmed AMI. The infarct size (based on cardiac MRI) in a subgroup of patients was not different between groups with and without O2 therapy. O2 therapy reduced the risk of hypoxaemia (OR, 0.29 (95% CI 0.17 to 0.47)).CONCLUSION:Although supplemental O2 therapy is commonly used, it was not associated with important clinical benefits. These findings from eight RCTs support departing from the usual practice of administering oxygen in normoxaemic patients