Y. Lamarche

Sutureless aortic valve replacement in patients who have bicuspid aortic valve

OBJECTIVEnBicuspid aortic valve (BAV) is generally considered to be a contraindication to sutureless aortic valve replacement (AVR). The aim of this study was to evaluate the feasibility and perioperative outcomes of this technique in patients with BAV.nnnMETHODSnFrom June 2011 to January 2014, a total of 25 patients who underwent sutureless AVR had documented BAV. Thirteen patients (52%) had median sternotomy, and 12 patients (48%) a minimally invasive approach.nnnRESULTSnThe study population included 17 (68%) men with a median age of 77.8 ± 5.4 years. The mean EuroSCORE II was 3.4% ± 2.6%. Concomitant procedures included coronary artery bypass grafting in 8 patients (32%), 2 AVRs (8%), 1 mitral valve repair (4%), 1 septal myomectomy (4%), and 1 atrial septal defect closure (4%). The mean transaortic valve gradient decreased from 49.4 ± 15.7, to 14.5 ± 5.4 mm Hg postoperatively. The mean aortic valve area increased from 0.78 ± 0.18, to 1.75 ± 0.43 cm(2) postoperatively. Five patients (20%) suffered from atrioventricular block that required permanent pacemaker implantation. Two patients (8%) suffered a stroke. No major paravalvular leakage occurred, and no postoperative valve migration. In-hospital mortality occurred in 1 patient (4%). The mean intensive care unit length of stay was 3 ± 2 days postoperatively.nnnCONCLUSIONSnThis study demonstrates that a sutureless aortic valve can be deployed in patients with BAV without increasing the risk of paravalvular leakage. BAV should not be considered a contraindication to sutureless AVR.

Hemodynamic instability and fluid responsiveness.

The rapid response team was called to evaluate a 64-yr-old hypotensive and hypoxic female patient hospitalized for deep venous thrombosis. Low-molecular-weight heparin had been initiated two days previously. The rapid response team observed her vital signs: heart rate, 110 beats min; blood pressure, 90/65 mmHg; and oxygen saturation, 90% while receiving 100% oxygen via a non-rebreather face mask. Using bedside focused ultrasonography, the patient’s inferior vena cava was found to be 2 cm and to collapse during inspiration. Lung ultrasonography revealed a spontaneous left-sided hemothorax. She was transferred to the intensive care unit, and a chest tube was inserted while coagulation was corrected using fresh frozen plasma. A chest radiograph confirmed the left-sided hemothorax. An inferior vena cava filter was inserted and the patient’s condition rapidly stabilized. She was discharged from hospital three days later. Interpretation

A Survey of Standardized Management Protocols After Coronary Artery Bypass Grafting Surgery in Canadian Intensive Care Units

BACKGROUNDnPatients undergoing surgical coronary revascularization typically recover in an intensive care unit where many aspects of patient care are protocolized despite absence of widespread evidence-based guidelines on perioperative management. It was hypothesized that the postoperative management strategies varied significantly among units.nnnMETHODSnWe surveyed 31 Canadian cardiac surgical intensive care units to obtain their postoperative standing orders. Management strategies after coronary bypass surgery were compared to identify areas of variability in the care of frequent clinical scenarios.nnnRESULTSnIn all, 28 units (90%) responded, and 26 sites (84%) reported using at least 1 formal postoperative protocol. All but 1 of the responding units (96%) have specific orders for coronary artery bypass graft patients. Orders for allogeneic red blood cell transfusion threshold, postoperative extubation pathway, analgesia, and atrial fibrillation management were present in 40%, 74%, 60%, and 57% of the responding units, respectively. A protocolized trigger to notify the surgeon was specified for bleeding and hypotension in 75% and 35% of the centres, respectively. A standing order for aspirin administration was used in 91% of the centres, and statin administration was mentioned in 41%. Despite the frequent use of protocols in postoperative care, the content of the protocol varied significantly from centre to centre.nnnCONCLUSIONnThe majority of Canadian centres use at least 1 formal protocol for the care of the postoperative coronary revascularization patient. There is, however, significant variability in these management protocols. Future studies should examine whether implementation of standardized protocols improves outcomes and what treatment strategies are optimal in postoperative cardiac surgical patients.

Differences and similarities in risk factors for postoperative acute kidney injury between younger and older adults undergoing cardiac surgery

Objectives Acute kidney injury is a frequent complication after cardiac surgery. The purpose of this study was to assess the risk factors for acute kidney injury in patients ≤60 years of age undergoing cardiac surgery and to compare these risk factors with those identified in patients ≥65 years of age. Methods From 2010 to 2012, 1253 patients ≤60 years (mean age 52 ± 9 years) and 2488 patients ≥65 years (mean age 74 ± 6 years) underwent cardiac surgery. Linear regression models using least absolute shrinkage and selection operator methods and mixed effects linear regression models were used to assess factors associated with maximum postoperative increase in serum creatinine in these two cohorts. Results In both age groups, the following variables were associated independently with greater degrees of postoperative increase in serum creatinine on multivariable analysis: greater body mass index, peripheral vascular disease, preoperative use of diuretics, lower preoperative hemoglobin, preoperative intra‐aortic balloon pump, urgent or emergent status, long cardiopulmonary bypass time, and hemofiltration. In younger patients, a greater increase in serum creatinine was associated with diabetes, and previous cardiac surgery, whereas female sex was associated with a lower degree of increase in serum creatinine. In older patients, a greater increase in serum creatinine was associated with age, hypertension, smoking, and lower left ventricular left ejection fraction. Operation type and coronary artery disease had a different impact on postoperative creatinine increase between younger and older patients. Conclusions This study identified both common and distinct risk factors associated with postoperative increase in serum creatinine between patients ≤60 years and those ≥65 years undergoing cardiac surgery. Importantly, all potentially modifiable risk factors were present in both groups.

Surgery Versus Transcatheter Interventions for Significant Paravalvular Prosthetic Leaks

OBJECTIVESnThis study sought to assess the relative merit of surgical correction (SC) versus transcatheter reduction onxa0long-term outcomes in patients with significant paravalvular leak (PVL) refractory to medical therapy.nnnBACKGROUNDnPVL is the most frequent dysfunction following prosthetic valve replacement. Although repeat surgery is the gold standard, transcatheter reduction (TR) of PVL has been associated with reduced mortality.nnnMETHODSnFrom 1994 to 2014, 231 patients underwent SC (nxa0= 151) or TR (nxa0= 80) PVL correction. Propensity matchingxa0and Cox proportional hazards regression models were used to assess the effect of either intervention on long-term rates of all-cause death or hospitalization for heart failure. Survival after TR and SC were further compared with the survival inxa0a matched general population and to matched patients undergoing their first surgical valve replacement.nnnRESULTSnOver a median follow-up of 3.5 years, SC was associated with an important reduction in all-causexa0deathxa0orxa0hospitalization for heart failure compared with TR (hazard ratio: 0.28; 95% confidence interval: 0.18xa0toxa00.44; pxa0<xa00.001). There was a trend towards reduced all-cause death following SC versusxa0TRxa0(hazardxa0ratio:xa00.61; 95%xa0confidence interval: 0.37 to 1.02; pxa0= 0.06). Neither intervention normalizedxa0survivalxa0whenxa0compared with axa0general population or patients undergoing their first surgical valvexa0replacement.nnnCONCLUSIONSnIn patients with significant prosthetic PVL, surgery is associated with better long-term outcomesxa0compared with transcatheter intervention, but results in important perioperative mortality and morbidity. Future studies are needed in the face of increasing implementation of transcatheter PVL interventions across thexa0world.

Assessment of fluid responsiveness with end-tidal carbon dioxide using a simplified passive leg raising maneuver: a prospective observational study

BackgroundAssessing fluid responsiveness is important in the management of patients with hemodynamic instability. Passive leg raising (PLR) is a validated dynamic method to induce a transient increase in cardiac preload and predict fluid responsiveness. Variations in end-tidal carbon dioxide (ETCO2) obtained by capnography correlate closely with variations in cardiac output when alveolar ventilation and carbon dioxide production are kept constant. In this prospective observational study, we tested the hypothesis that variations in ETCO2xa0induced by a simplified PLR maneuver can track changes in the cardiac index (CI) and thus predict fluid responsiveness.MethodA five-minute standardized PLR maneuver was performed in 90 paralyzed hemodynamically stable cardiac surgical patients receiving mechanical ventilation. Cardiac index was measured by thermodilution before and one minute after PLR. End-tidal CO2xa0measurements using capnography were obtained during the entire PLR maneuver. Fluid responsiveness was defined as a 15% increase in the CI. The Chi square test and Student’s t test were used to compare responders and non-responders. Logistic regression analyses were then performed to determine factors of responsiveness.ResultsThere were no differences between responders and non-responders in demographic and baseline hemodynamic variables. Fluid responsiveness was associated with an ETCO2 variation (ΔETCO2) of ≥ 2 mmHgxa0during PLR [odds ratio (OR), 7.3; 95% confidence interval (CI), 2.7 to 20.2; P < 0.01; sensitivity 75%]. A low positive predictive value (54%) and a high negative predictive value (NPV) (86%) were observed. No other clinical or hemodynamic predictors were associated with fluid responsiveness. A logistic regression model established that a combination of ΔETCO2 ≥ 2 mmHg and a change in systolic blood pressure ≥ 10 mmHg induced by passive leg raising was predictive of fluid responsiveness (OR, 8.9; 95% CI, 2.5 to 32.2; P = 0.005).ConclusionUse of a passive leg raising maneuver to induce variation in ETCO2xa0is a noninvasive and useful method to assess fluid responsiveness in paralyzed cardiac surgery patients receiving mechanical ventilation. Given its high NPV, fluid responsiveness is unlikely if a passive leg raising maneuver induces ΔETCO2 of < 2 mmHg.RésuméContexteL’évaluation de la réponse au remplissage est importante dans la prise en charge des patients souffrant d’instabilité hémodynamique. L’élévation passive des jambes (EPJ) est une méthode dynamique validée pour induire une augmentation transitoire de la précharge cardiaque et prédire la réponse au remplissage. Les variations en matière de dioxyde de carbone télé-expiratoire (ETCO2) obtenues par capnographie sont étroitement corrélées aux variations de débit cardiaque lorsque la ventilation alvéolaire et la production de dioxyde de carbone sont maintenues constantes. Dans cette étude observationnelle prospective, nous avons testé l’hypothèse selon laquelle les variations de l’ETCO2xa0induites par une manœuvre simplifiée d’EPJ peuvent refléter les changements d’index cardiaque (IC) et ainsi prédire la réponse au remplissage.MéthodeUne manœuvre d’EPJ standardisée de cinq minutes a été réalisée auprès de 90 patients de chirurgie cardiaque hémodynamiquement stables et curarisés recevant une ventilation mécanique. L’index cardiaque a été mesuré par thermodilution avant et une minute après la manœuvre. Les mesures de CO2 télé-expiratoire ont été obtenues par capnographie tout au long de la manœuvre d’EPJ. On a défini la réponse au remplissage en tant qu’une augmentation de 15 % de l’IC. Le test de Chi carré et le test t de Student ont été utilisés pour comparer les répondants et les non-répondants. Des analyses de régression logistique ont ensuite été réalisées afin de déterminer les facteurs de réponse.RésultatsAucune différence n’a été observée entre les répondants et les non-répondants en matière de variables démographiques ou hémodynamiques de base. La réponse au remplissage a été associée à une variation d’ETCO2 (ΔETCO2) ≥ 2 mmHg pendant la manœuvre d’EPJ [rapport de cotes (RC), 7,3; intervalle de confiance (IC) 95 %, 2,7 à 20,2; P < 0,01; sensibilité 75xa0%]. Une valeur prédictive positive basse (54 %) et une valeur prédictive négative élevée (VPN) (86 %) ont été observées. Aucun autre prédicteur clinique ou hémodynamique n’a été associé à la réponse au remplissage. Le modèle de régression logistique a établi qu’une combinaison de ΔETCO2 ≥ 2 mmHg et une modification de la pression artérielle systolique ≥ 10 mmHg induite par une élévation passive des jambes était un prédicteur de réponse au remplissage (RC, 8,9; IC 95 %, 2,5 to 32,2; P = 0,005).ConclusionL’utilisation d’une manœuvre d’élévation passive des jambes pour induire des variations d’ETCO2xa0constitue une méthode non invasive et utile pour évaluer la réponse au remplissage chez des patients de chirurgie cardiaque paralysés recevant une ventilation mécanique. Étant donné sa VPN élevée, la réponse au remplissage est peu probable si une manœuvre d’élévation passive des jambes induit une ΔETCO2 < 2 mmHg.

Prehospital Advanced Cardiac Life Support for Out‐of‐hospital Cardiac Arrest: A Cohort Study

OBJECTIVESnOut-of-hospital advanced cardiac life support (ACLS) has not consistently shown a positive impact on survival. Extracorporeal cardiopulmonary resuscitation (E-CPR) could render prolonged on-site resuscitation (ACLS or basic cardiac life support [BCLS]) undesirable in selected cases. The objectives of this study were to evaluate, in patients suffering from out-of-hospital cardiac arrest (OHCA) and in a subgroup of potential E-CPR candidates, the association between the addition of prehospital ACLS to BCLS and survival to hospital discharge, prehospital return of spontaneous circulation (ROSC), and delay from call to hospital arrival.nnnMETHODSnThis cohort study targets adult patients treated for OHCA between April 2010 and December 2015 in the city of Montreal, Canada. We defined potential E-CPR candidates using clinical criteria previously described in the literature (65 years of age or younger, initial shockable rhythm, absence of ROSC after 15 minutes of prehospital resuscitation, and emergency medical services-witnessed collapse or witnessed collapse with bystander cardiopulmonary resuscitation). Associations were evaluated using multivariate regression models.nnnRESULTSnA total of 7,134 patients with OHCA were included, 761 (10.7%) of whom survived to discharge. No independent association between survival to hospital discharge and the addition of prehospital ACLS to BCLS was found in either the entire cohort (adjusted odds ratio [AOR] = 1.05 [95% confidence interval {CI} = 0.84-1.32], p = 0.68) or among the 246 potential E-CPR candidates (AOR = 0.82 [95% CI = 0.36-1.84], p = 0.63). The addition of prehospital ACLS to BCLS was associated with a significant increase in the rate of prehospital ROSC in all patients experiencing OHCA (AOR = 3.92 [95% CI = 3.38-4.55], p < 0.001) and in potential E-CPR candidates (AOR = 3.48 [95% CI = 1. 76-6.88], p < 0.001) compared to isolated prehospital BCLS. Delay from call to hospital arrival was longer in the ACLS group than in the BCLS group (difference = 16 minutes [95% CI = 15-16 minutes], p < 0.001).nnnCONCLUSIONSnIn a tiered-response urban emergency medical service setting, prehospital ACLS is not associated with an improvement in survival to hospital discharge in patients suffering from OHCA and in potential E-CPR candidates, but with an improvement in prehospital ROSC and with longer delay to hospital arrival.

Impact of the direct transfer to percutaneous coronary intervention-capable hospitals on survival to hospital discharge for patients with out-of-hospital cardiac arrest

AIMSnPatients suffering from out-of-hospital cardiac arrest (OHCA) are frequently transported to the closest hospital. Percutaneous coronary intervention (PCI) is often indicated following OHCA. This studys primary objective was to determine the association between being transported to a PCI-capable hospital and survival to discharge for patients with OHCA. The additional delay to hospital arrival which could offset a potential increase in survival associated with being transported to a PCI-capable center was also evaluated.nnnMETHODSnThis study used a registry of OHCA in Montreal, Canada. Adult patients transported to a hospital following a non-traumatic OHCA were included. Hospitals were dichotomized based on whether PCI was available on-site or not. The effect of hospital type on survival to discharge was assessed using a multivariable logistic regression. The added prehospital delay which could offset the increase in survival associated with being transported to a PCI-capable center was calculated using that regression.nnnRESULTSnA total of 4922 patients were included, of whom 2389 (48%) were transported to a PCI-capable hospital and 2533 (52%) to a non-PCI-capable hospital. There was an association between being transported to a PCI-capable center and survival to discharge (adjusted odds ratiou202f=u202f1.60 [95% confidence interval 1.25-2.05], pu202f<u202f.001). Increasing the delay from call to hospital arrival by 14.0u202fmin would offset the potential benefit of being transported to a PCI-capable center.nnnCONCLUSIONSnIt could be advantageous to redirect patients suffering from OHCA patients to PCI-capable centers if the resulting expected delay is of less than 14u202fmin.

Potential impact of a prehospital redirection system for refractory cardiac arrest

AIMnA change in prehospital redirection practice could potentially increase the proportion of E-CPR eligible patients with out-of-hospital cardiac arrest (OHCA) transported to extracorporeal cardiopulmonary resuscitation (E-CPR) capable centers. The objective of this study was to quantify this potential increase of E-CPR candidates transported to E-CPR capable centers.nnnMETHODSnAdults with non-traumatic OHCA refractory to 15min of resuscitation were selected from a registry of adult OHCA collected between 2010 and 2015 in Montreal, Canada. Using this cohort, three simulation scenarios allowing prehospital redirection to E-CPR centers were created. Stringent eligibility criteria for E-CPR and redirection for E-CPR (e.g. age <60years old, initial shockable rhythm) were used in the first scenario, intermediate eligibility criteria (e.g. age <65years old, at least one shock given) in the second scenario and inclusive eligibility criteria (e.g. age <70years old, initial rhythm ≠ asystole) in the third scenario. All three scenarios were contrasted with equivalent scenarios in which patients were transported to the closest hospital. Proportions were compared using McNemars test.nnnRESULTSnThe proportion of E-CPR eligible patients transported to E-CPR capable centers increased in each scenario (stringent criteria: 48 [24.5%] vs 155 patients [79.1%], p<0.001; intermediate criteria: 81 [29.6%] vs 262 patients [95.6%], p<0.001; inclusive criteria: 238 [23.9%] vs 981 patients [98.5%], p<0.001).nnnCONCLUSIONSnA prehospital redirection system could significantly increase the number of patients with refractory OHCA transported to E-CPR capable centers, thus increasing their access to this potentially life-saving procedure, provided allocated resources are planned accordingly.