Guide extension catheters: Review of technology and future directions.

Although Percutaneous Coronary Intervention (PCI) has revolutionized the management of CAD, the deliverability of devices including balloons, specialty balloons, stents, atherectomy catheters, thrombectomy devices, and intravascular lithotripsy devices has become a common challenge faced by interventional cardiologists. Guide Extension Catheters (GECs) have been developed and are now widely used to create improved backup support to allow the advancement of interventional equipment required for the PCI. Improved lesion preparation, plaque modification (e.g., with atherectomy), and Guide Extension Catheters (GEC), also called as Mother-Child Technique, has proven critical to procedural success in complex cases. In this review, we discuss the role and limitations of current guide extension devices, with a brief discussion of next-generation GEC.

Postdischarge-to-30-Day Mortality Among Patients Receiving MitraClip: A Systematic Review and Meta-Analysis.

Background: MitraClip (MC) implantation is the recommended treatment for severe symptomatic mitral regurgitation in patients not responding to medical therapy and at prohibitive surgical risk. It is important to quantify immediate mortality during postdischarge-to-30-day period so as to improve the procedural outcomes. Hence, we aim to identify the incidence of postdischarge-to-30-day mortality and its associated predictors using the technique of meta-analysis. Methods: We searched Medline, Embase, and Cochrane CENTRAL databases from inception until July 3, 2019 for studies reporting mortality prior to discharge, at 30 days and 1 year after MC implantation. The primary outcome was postdischarge-to-30-day all-cause mortality. Results: Of 2394 references, 15 studies enrolling 7498 patients were included. Random effects analysis showed that all-cause cumulative inpatient, 30-day, and 1-year mortality was 2.40% (2.08, 2.77; I2 = 0%), 4.31% (3.64, 5.09, I2 = 41.9%), and 20.71% (18.32; 23.33, I2 = 81.5%), respectively. The postdischarge-to-30-day mortality was 1.70% (95% confidence interval: 1.0, 2.70; I2 = 84%). A total of 71.50% of deaths (95% confidence interval: 36.80-91.50, I2 = 63%) in the postdischarge-to-30-day period were due to cardiac etiology. On meta-regression, pre-MC left ventricular ejection fraction (p = 0.003), Log.Euroscore (p = 0.047), Society of Thoracic Surgeons Predicted Risk of Mortality (p < 0.001), and prolonged ventilation >48 ​hours (p < 0.001) were found to be its significant predictors. Conclusions: Our meta-analysis reports an additional mortality of ∼2% immediately after MC implantation during the postdischarge-to-30-day period. Majority of deaths occurred due to cardiac causes. Pre-MC left ventricular ejection fraction, Log.Euroscore, Society of Thoracic Surgeons Predicted Risk of Mortality score, and prolonged ventilation were found to be its significant predictors. Further studies are needed to better understand the causes of this early mortality to maximize benefits of this important therapy.

Postoperative Myocardial Injury in Patients Classified as Low Risk Preoperatively Is Associated With a Particularly Increased Risk of Long-Term Mortality After Noncardiac Surgery.

Background Prior studies have shown an association between myocardial injury after noncardiac surgery (MINS) and all-cause mortality in patients following noncardiac surgery. However, the association between preoperative risk assessments, Revised Cardiac Risk Index and American College of Surgeons National Surgical Quality Improvement Program, and postoperative troponin elevations and long-term mortality is unknown. Methods and Results A retrospective chart review identified 548 patients who had a troponin I level drawn within 14 days of noncardiac surgery that required an overnight hospital stay. Patients aged 40 to 80 years with at least 2 cardiovascular risk factors were included, while those with trauma, pulmonary embolism, and neurosurgery were excluded. Kaplan-Meier survival and odds ratio (OR) with sensitivity/specificity analysis were performed to assess the association between preoperative risk and postoperative troponin elevation and all-cause mortality at 1 year. Overall, 69%/31% were classified as low-risk/high-risk per the Revised Cardiac Risk Index and 66%/34% per American College of Surgeons National Surgical Quality Improvement Program. Comparing the low-risk versus high-risk groups, preoperative risk assessment was not associated with either postoperative troponin elevation or 1-year mortality. MINS portended a 1-year mortality of OR, 3.9 (95% CI, 2.44-6.33) in the total population. Patients classified as low risk preoperatively with MINS had the highest risk of 1-year mortality (OR, 9.6; 95% CI, 4.27-24.38), with a low prevalence of statin use. Conclusions Current preoperative risk stratification tools do not prognosticate the risk of postoperative troponin elevation and all-cause mortality at 1 year. Interestingly, patients classified as low risk preoperatively with MINS had a markedly higher 1-year mortality risk compared with the general population, and most of them are not taking a statin. Our results suggest that evaluating preoperatively low-risk patients for MINS presents an opportunity for prognostication, risk reclassification, and initiating therapies such as statins to mitigate long-term risk.

Multidisciplinary rounds in prevention of 30-day readmissions and decreasing length of stay in heart failure patients: A community hospital based retrospective study.

To assess the impact of multidisciplinary rounds (MDR) on 30-day readmissions and length of stay in hospitalized patients with a diagnosis of congestive heart failure in a community teaching hospital.Patients with primary admission diagnosis of congestive heart failure (CHF) were included. A before and after retrospective study was conducted once the intervention was implemented in 2014. The before and after study periods were each of 1-year duration and included 181 and 151 patients, respectively. Our multidisciplinary heart failure rounding team consisted of a staff cardiologist, case manager, pharmacist, social worker, and a nutritionist.The mean length of stay decreased from 5.7 days to 5 days, and 30-day readmissions decreased from 27.6% to 17.22% (P-value .026) after implementation of the multidisciplinary rounding. We observed a significant decrease of readmissions in ischemic cardiomyopathy (ICM) (from 33.61% to 14.01%; P-value .007) and heart failure with reduced ejection fraction (HFrEF) (from 31.34% to 16.05%; P-value .028) patients. There was an increase in the percentage of patients hospitalized with non-ischemic cardiomyopathy (NICM) and heart failure with preserved ejection fraction (HFpEF) and, in particular, women patients with heart failure.Implementation of MDR program on CHF patients resulted in significant decrease in both readmission rate and length of stay in our hospital.

Effect of high flow transnasal dry air on core body temperature in intubated human subjects.

PURPOSE: Early initiation of hypothermia is recommended in the setting of cardiac arrest. Current hypothermia methods are invasive and expensive and not applicable in ambulatory settings. We investigated the evaporative cooling effect of high flow transnasal dry air on core esophageal temperature in human volunteers. METHODS & RESULTS: A total of 32 subjects (mean age 53.2 ± 9.3 yrs., mean weight 90 ± 17 kg) presenting for elective electrophysiological procedures were enrolled for the study. Half of the subjects were men. Following general anesthesia induction, high flow (30 LPM) medical grade ambient dry air with a relative humidity ∼20% was administered through a nasal mask for 60 min. Core temperature was monitored at the distal esophagus. Half of the subjects (16/32) were subject to high flow air and the remainder served as controls. Over a 1-h period, mean esophageal temperature decreased from 36.1 ± 0.3 °C to 35.5 ± 0.1 °C in the test subjects (p < 0.05). No significant change in temperature was observed in the control subjects (36.3 ± 0.3 °C to 36.2 ± 0.2 °C, p = NS). No adverse events occurred. CONCLUSION: Transnasal high flow dry air through the nasopharynx reduces core body temperature. This mechanism can be harnessed to induce hypothermia in patients where clinically indicated without any deleteriouseffects in a short time exposure.

Efficacy and Safety of Transnasal CoolStat Cooling Device to Induce and Maintain Hypothermia.

Targeted temperature management (TTM) is recommended as a standard of care for postcardiac arrest patients. Current TTM methods have significant limitations to be used in an ambulatory setting. We investigated the efficacy and safety of a novel noninvasive transnasal evaporative cooling device (CoolStat™). Eleven Yorkshire pigs underwent hypothermia therapy using the CoolStat device. CoolStat induces evaporative cooling by blowing dehumidified ambient air over the nasal turbinates in a unidirectional fashion. CoolStat's efficacy and safety were assessed by applying different cooling strategies (groups A, B and C). In group A (efficacy study; n = 5, TTM for 8 hours), time to achieve brain target temperature (2°C reduction from baseline), and the percentage of time in which the temperature ranged within ±0.5°C after reaching the target temperature were investigated. In the safety assessment (groups B and C), two worst-case therapy situations were reproduced: in group B (n = 3), continuous maximum air flow (65 L/min) was applied without temperature control and, in group C (n = 3), subjects underwent 24-hour TTM (prolonged therapy). Hemodynamic and respiratory parameters, nasal mucosa integrity (endoscopic assessment), and other therapy-related adverse effects were evaluated. Efficacy study: CoolStat cooling therapy successfully induced and sustained managed hypothermia in all subjects. Brain target temperature was achieved in 0.5 ± 0.6 hours and kept within a ±0.5°C range for the therapy duration (99.9% ± 0.1%). All animals completed the safety studies. Maximum air flow (group B) and 24-hour (group C) therapies were well tolerated and no significant damage was observed on nasal mucosa for neither of the groups. CoolStat was able to efficiently induce and maintain hypothermia using unidirectional high flow of dry air into the nostrils of porcine models. CoolStat therapy was well tolerated and no damage to nasal mucosa was observed under either maximum air flow or prolonged therapy.

Segmented radial cardiac MRI during arrhythmia using retrospective electrocardiogram and respiratory gating.

PURPOSE: To improve segmented cardiac MRI image quality during arrhythmia. METHODS: Electrocardiogram (ECG) and respiratory waveforms were recorded during imaging. Imaging readouts were retrospectively classified into heartbeat-types based on the RR interval of the current and preceding beats, QRS morphology, and respiratory phase. Image data were sorted by these classifiers to generate separate cine images of different heartbeat-types during sinus rhythm and arrhythmia. A simulation study evaluated the efficiency of K-space sampling over a range of heart rhythms, heart rates, and respiratory rates. In vivo imaging was performed in volunteers with sinus rhythm, swine with arrhythmia simulated by pacing, and a human subject with spontaneous premature beats. RESULTS: K-space sampling uniformity and image quality incrementally improve with additional occurrences of the desired normal sinus or arrhythmia heartbeat-type. To approach the image quality of breath-hold imaging, sufficiently restrictive gating parameters are required. Compared with real-time imaging, retrospective gated images had reduced noise and improved sharpness while maintaining desired cine temporal resolution. Variations of cardiac function between arrhythmia heartbeats could be observed in arrhythmia imaging cases that are not captured by conventional segmented imaging. CONCLUSION: Retrospective ECG and respiratory gating permits imaging of various heartbeats during arrhythmia with fewer resolution restrictions compared to real-time imaging. For a fixed imaging time, imaging quality depends on frequency of the imaged heartbeat-type. Imaging additional heartbeats permits incremental improvement in image quality.

Left Atrial Appendage Occlusion: What Are the Options and Where is the Evidence?

Left atrial appendage occlusion (LAAO) has emerged as an effective site-directed therapy in patients with nonvalvular atrial fibrillation (AF) for stroke prevention, who are ineligible for long-term oral anticoagulation. The objective of this study was to assess the safety, efficacy, and availability of LAAO devices by reviewing the literature and to review the development and effectiveness of LAAO by the transcatheter approach with plugging devices such as WATCHMAN™ (Boston Scientific, Natick, MA, USA); AMPLATZER™ Cardiac Plug and AMPLATZER™ Amulet™ (Abbott Laboratories, Chicago, IL, USA); and the LARIAT® Suture Delivery Device (SentreHEART, Redwood City, CA, USA), which features an entirely unique hybrid (endocardial and epicardial) approach in closing the left atrial appendage (LAA). The conducted literature review ultimately revealed a substantial body of literature supporting the safety and efficacy of various LAAO strategies, including endocardial, epicardial, and hybrid approaches, in AF patients who are not eligible for long-term oral anticoagulant use. Specifically, the most attractive population suitable for LAA closure appears to be patients at high risk for ischemic stroke with a longer life expectancy but a moderate-to-high bleeding risk with long-term oral anticoagulation. The benefit of LAA closure in reducing the incidence of stroke in patients with nonvalvular AF has been evolving gradually, and we are confident that this new field of percutaneous LAA closure will continue to emerge as a game-changer in the treatment of AF.

Rapid Induction of Therapeutic Hypothermia Using Transnasal High Flow Dry Air.

Early induction of therapeutic hypothermia (TH) is recommended in out-of-hospital cardiac arrest (CA); however, currently no reliable methods exist to initiate cooling. We investigated the effect of high flow transnasal dry air on brain and body temperatures in adult porcine animals. Adult porcine animals (n = 23) under general anesthesia were subject to high flow of transnasal dry air. Mouth was kept open to create a unidirectional airflow, in through the nostrils and out through the mouth. Brain, internal jugular, and aortic temperatures were recorded. The effect of varying airflow rate and the air humidity (0% or 100%) on the temperature profiles were recorded. The degree of brain cooling was measured as the differential temperature from baseline. A 10-minute exposure of high flow dry air caused rapid cooling of brain and gradual cooling of the jugular and the aortic temperatures in all animals. The degree of brain cooling was flow dependent and significantly higher at higher airflow rates (0.8°C ± 0.3°C, 1.03°C ± 0.6°C, and 1.3°C ± 0.7°C for 20, 40, and 80 L, respectively, p < 0.05 for all comparisons). Air temperature had minimal effect on the brain cooling over 10 minutes with similar decrease in temperature at 4°C and 30°C. At a constant flow rate (40 LPM) and temperature, the degree of cooling over 10 minutes during dry air exposure was significantly higher compared to humid air (100% saturation) (1.22°C ± 0.35°C vs. 0.21°C ± 0.12°C, p < 0.001). High flow transnasal dry air causes flow dependent cooling of the brain and the core temperatures in intubated porcine animals. The mechanism of cooling appears to be evaporation of nasal mucus as cooling is mitigated by humidifying the air. This mechanism may be exploited to initiate TH in CA.