Rashid M. Ahmad

Etomidate Use and Postoperative Outcomes among Cardiac Surgery Patients

Background:Although a single dose of etomidate can cause relative adrenal insufficiency, the impact of etomidate exposure on postoperative outcomes is unknown. The objective of this study was to examine the association between a single induction dose of etomidate and clinically important postoperative outcomes after cardiac surgery. Methods:The authors retrospectively examined the association between etomidate exposure during induction of anesthesia and postoperative outcomes in patients undergoing cardiac surgery from January 2007 to December 2009 by using multivariate logistic regression analyses and Cox proportional hazards regression analyses. Postoperative outcomes of interest were severe hypotension, mechanical ventilation hours, hospital length of stay, and in-hospital mortality. Results:Sixty-two percent of 3,127 patients received etomidate. Etomidate recipients had a higher incidence of preoperative congestive heart failure (23.0 vs. 18.3%; P = 0.002) and a lower incidence of preoperative cardiogenic shock (1.3 vs. 4.0%; P < 0.001). The adjusted odds ratio for severe hypotension and in-hospital mortality associated with receiving etomidate was 0.80 (95% CI, 0.58–1.09) and 0.75 (95% CI, 0.45–1.24), respectively, and the adjusted hazard ratio for time to mechanical ventilation removal and time to hospital discharge was 1.10 (95% CI, 1.00–1.21) and 1.07 (95% CI, 0.97–1.18), respectively. Propensity score analysis did not change the association between etomidate use and postoperative outcomes. Conclusions:In this study, there was no evidence to suggest that etomidate exposure was associated with severe hypotension, longer mechanical ventilation hours, longer length of hospital stay, or in-hospital mortality. Etomidate should remain an option for induction of anesthesia in cardiac surgery patients.

Episodic Monoplane Transesophageal Echocardiography Impacts Postoperative Management of the Cardiac Surgery Patient

OBJECTIVE A new slender, flexible, and miniaturized disposable monoplane transesophageal TEE probe has been approved for episodic hemodynamic transesophageal echocardiographic monitoring. The authors hypothesized that episodic monoplane TEE with a limited examination would help guide the postoperative management of high-risk cardiac surgery patients. DESIGN The authors analyzed the initial consecutive observational experience with the miniaturized transesophageal echocardiography monitoring system (ClariTEE, ImaCor, Uniondale, New York). SETTING Single institution in a university setting. PARTICIPANTS Unstable cardiac surgery patients. INTERVENTIONS The authors assessed fluid responsiveness, echocardiographic data, and concordance among hemodynamic data. MEASUREMENTS AND MAIN RESULTS From June 2010 to February 2011, 21 unstable cardiac surgery patients with postoperative instability were identified. Two patients (10%) required reoperation for bleeding and tamponade physiology. Right ventricular dysfunction was diagnosed by episodic TEE monitoring in 7 patients (33%), while hypovolemia was documented in 12 patients (57%). Volume responsiveness was documented in 11 patients. In this observational study, discordance between hemodynamic monitoring and episodic TEE was qualitatively observed in 14 patients (66%). CONCLUSION The authors demonstrated the ability of episodic monoplane TEE to identify discordance between hemodynamic monitoring to better define clinical scenarios in unstable cardiac surgery patients. For these challenging patients, limited episodic TEE assessment has become a cornerstone of ICU care in this institution.

Left thoracotomy HeartWare implantation with outflow graft anastomosis to the descending aorta: a simplified bridge for patients with multiple previous sternotomies.

Advances in mechanical circulatory support have been critical in bridging patients awaiting heart transplantation. In addition, improvement in device durability has enabled left ventricular assist device therapy to be applied as destination therapy in those not felt to be transplant candidate. Because of the increasing complexity of patients, there continues to be a need for alternative strategies for device implantation to bridge high-risk patients awaiting heart transplantation, wherein the risks of numerous previous sternotomies may be prohibitive. We present a unique technique for placement of the HeartWare ventricular assist device via left anterior thoracotomy to the descending aorta in a patient awaiting heart transplantation with a history of multiple previous sternotomies.

Minimally invasive mitral valve surgery expands the surgical options for high-risks patients.

Background:A simplified minimally invasive mitral valve surgery (MIMVS) approach avoiding cross-clamping and cardioplegic myocardial arrest using a small (5 cm) right antero-lateral incision was developed. We hypothesized that, in high-risk patients and in patients with prior sternotomy, this approach would yield superior results compared to those predicted by the Society of Thoracic Surgeons (STS) algorithm for standard median sternotomy mitral valve surgery. Methods:Five hundred and four consecutive patients (249 males/255 females), median age 65 years (range 20–92 years) underwent MIMVS between 1/06 and 8/09. Median preoperative New York Heart Association function class was 3 (range 1–4). Eighty-two (16%) patients had an ejection fraction ⩽35%. Forty-seven (9%) had a STS predicted mortality ≥10%. Under cold fibrillatory arrest (median temperature 28°C) without aortic cross-clamp, mitral valve repair (224/504, 44%) or replacement (280/504, 56%) was performed. Results:Thirty-day mortality for the entire cohort was 2.2% (11/504). In patients with a STS predicted mortality ≥ 10% (range 10%–67%), the observed 30-day mortality was 4% (2/47), lower than the mean STS predicted mortality of 20%. Morbidity in this high-risk group was equally low: 1 of 47 (2%) patients underwent reexploration for bleeding, 1 of 47 (2%) patients suffered a permanent neurologic deficit, none had wound infection. The median length of stay was 8 days (range 1–68 days). Conclusions:This study demonstrates that MIMVS without aortic cross-clamp is reproducible with low mortality and morbidity rates. This approach expands the surgical options for high-risk patients and yields to superior results than the conventional median sternotomy approach.

Benefits of ambulatory axillary intra-aortic balloon pump for circulatory support as bridge to heart transplant.

OBJECTIVE Axillary intra-aortic balloon pump therapy has been described as a bridge to transplant. Advantages over femoral intra-aortic balloon pump therapy include reduced incidence of infection and enhanced patient mobility. We identified the patients who would benefit most from this therapy while awaiting heart transplantation. METHODS We conducted a single-center, retrospective observational study to evaluate outcomes from axillary intra-aortic balloon pump therapy. These included hemodynamic parameters, duration of support, and success in bridging to transplant. We selected patients on the basis of history of sternotomy, elevated panel-reactive antibody, and small body habitus. Patients were made to ambulate aggressively beginning on postoperative day 1. RESULTS Between September 2007 and September 2010, 18 patients underwent axillary intra-aortic balloon pump therapy. All patients had the devices placed through the left axillary artery with a Hemashield side graft (Boston Scientific, Natick, Mass). Before axillary placement, patients underwent femoral placement to demonstrate hemodynamic benefit. Duration of support ranged from 5 to 63 days (median = 19 days). There was marked improvement in ambulatory potential and hemodynamic parameters, with minimal blood transfusion requirements. There were no device-related infections. Some 72% of the patients (13/18) were successfully bridged to transplantation. CONCLUSIONS Axillary intra-aortic balloon pump therapy provides excellent support for selected patients as a bridge to transplant. The majority of the patients were successfully bridged to transplant and discharged. Although this therapy has been described in previous studies, this is the largest series to incorporate a regimen of aggressive ambulation with daily measurements of distances walked.

Mechanical Circulatory Support and Heart Transplantation: Donor and Recipient Factors Influencing Graft Survival

BACKGROUND Mechanical circulatory support is an accepted strategy to bridge patients to heart transplantation (HTx). Among mechanical circulatory support patients who go on to HTx, factors associated with improved graft survival have not been fully elucidated. METHODS Using the Scientific Registry for Transplant Recipients, we identified adults who were treated with a left ventricular assist device (LVAD) or total artificial heart (TAH) before HTx. Kaplan-Meier and multivariate Cox regression models were used to identify patient, donor, and device characteristics associated with graft survival. RESULTS Between January 1997 and February 2012, 2,785 adults underwent HTx. Before HTx, 2,674 patients were treated with a LVAD (HeartMate XVE, 724; HeartMate II, 1,882; HeartWare, 68), and 111 were treated with a TAH. Follow-up averaged 25 ± 24 months. Gender mismatch occurred in 23%. Graft survival did not differ between LVAD groups (all p > 0.168), but TAH was associated with reduced graft survival compared with LVADs (p < 0.001). After controlling for device type (LVAD vs TAH), lower recipient pulmonary vascular resistance, shorter ischemic time, younger donor age, donor-to-recipient gender match, and higher donor-to-recipient body mass index ratio were independent predictors of longer graft survival (all p < 0.05). CONCLUSIONS TAH was associated with reduced graft survival after transplant, and survival did not differ between the LVAD device groups. Additional variables that were independently associated with graft survival were donor age, recipient peripheral vascular resistance, ischemic time, gender match, and donor-to-recipient body mass index ratio. Recognition of these factors may inform decisions regarding device support and donor suitability.

Perioperative Blood Product Use: A Comparison Between HeartWare and HeartMate II Devices

BACKGROUND The HeartWare (HW) (Framingham, MA) and the HeartMate II (HM II) (Thoratec Inc, Pleasanton, CA) continuous-flow left ventricular assist devices (CF-LVADs) are commonly used to bridge patients to transplantation. We hypothesized that there are differences in perioperative blood product (BP) use and chest tube (CT) output between CF-LVAD types. METHODS We retrospectively evaluated BP use in 71 patients who were implanted with a CF-LVAD (HM II = 38; HW = 33) by median sternotomy for bridge to transplantation (BTT) indications from 2009 to 2013. Detailed BP use data were collected during the intraoperative and postoperative periods and included packed red blood cells, platelets, fresh frozen plasma, and cryoprecipitate. RESULTS Preoperative characteristics (age, left ventricular ejection fraction, previous sternotomy, ischemic cause), and risk stratification scores (Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS]) profile, Leitz-Miller score, Kormos score) were comparable between groups (all p > 0.05). Total average intraoperative and postoperative BP use was different between device types: HW = 8.3 ± 13 versus HM II = 12.6 ± 14.0 units (p = 0.002) and HW = 6.1 ± 12.0 units compared with HM II = 13.5 ± 24.1 units (p = 0.022), respectively. Average postoperative CT output for HW (3,231 ± 3,648 mL) and HM II (3,463 ± 3,050) (p < 0.008) were different between device types. Multivariate analysis revealed that a higher preoperative Leitz-Miller score, implantation of an HM II CF-LVAD, previous sternotomy, and a longer duration of cardiopulmonary bypass (CPB) time were independently associated with increased need for BP use, whereas only use of the HM II device and a longer bypass time predicted a greater CT output. CONCLUSIONS Compared with HM II, implantation of the HW CF-LVAD was associated with reduced intraoperative and postoperative BP use and decreased CT output. Increased awareness of device-related differences in bleeding and BP use may improve CF-LVAD patient outcomes.

Results of Completion Arteriography After Minimally Invasive Off-Pump Coronary Artery Bypass

BACKGROUND The benefits of a minimally invasive approach to off-pump coronary artery bypass remain controversial. The value of completion arteriography in validating this technique has not been investigated. METHODS From April 2007 to October 2009, fifty-six patients underwent isolated minimally invasive coronary artery bypass grafting through a left thoracotomy without cardiopulmonary bypass. Forty-three of these patients underwent completion arteriography. RESULTS Sixty-five grafts were performed in these 56 patients, (average, 1.2 grafts per patient; range, 1 to 3). Forty-eight grafts were studied in the 43 patients undergoing completion arteriography. There were 4 findings on arteriogram leading to further immediate intervention (8.3%). These included 3 grafts with anastomotic stenoses or spasm requiring stent placement, and 1 patient who had limited dissection in the left internal mammary artery graft and underwent placement of an additional vein graft. These findings were independent of electrocardiographic changes or hemodynamic instability. The remainder of the studies showed no significant abnormalities. There were no deaths. One patient who did not have a completion arteriogram suffered a postoperative myocardial infarction requiring stent placement for anastomotic stenosis. Patients were discharged home an average of 6.8 days postoperatively. There were no instances of renal dysfunction postoperatively attributable to catheterization. CONCLUSIONS Minimally invasive coronary artery bypass is safe and effective. Findings of completion arteriography occasionally reveal previously under-recognized findings that, if corrected in a timely fashion, could potentially impact graft patency and clinical outcomes. Our experience validates this minimally invasive technique.

Institutional volume of heart transplantation with left ventricular assist device explantation influences graft survival.

BACKGROUND There are increasing numbers of patients undergoing orthotopic heart transplantation (OHT) with left ventricular assist device (LVAD) explantation (LVAD explant-OHT). We hypothesized that LVAD explant-OHT is a more challenging surgical procedure compared to OHT without LVAD explantation and that institutional LVAD explant-OHT procedural volume would be associated with post-transplant graft survival. We sought to assess the impact of institutional volume of LVAD explant-OHT on post-transplant graft survival. METHODS This is a retrospective analysis of the Scientific Registry of Transplant Recipients for adult OHTs with long-term LVAD explantation. LVAD explant-OHT volume was characterized on the basis of the centers year-specific total OHT volume (OHTvol) and year-specific LVAD explant-OHT volume quartile (LVADvolQ). The effect of LVADvolQ on graft survival (death or re-transplantation) was analyzed. RESULTS From 2004 to 2011, 2,681 patients underwent OHT with LVAD explantation (740 with HeartMate XVE, 1,877 with HeartMate II and 64 with HeartWare devices). LVAD explant-OHT at centers falling in the lowest LVADvolQ was associated with reduced post-transplant graft survival (p = 0.022). After adjusting for annualized OHTvol (HR = 0.998, 95% CI 0.993 to 1.003, p = 0.515 and pulsatile XVE (HR = 0.842, 95% CI 0.688 to 1.032, p = 0.098), multivariate analysis confirmed a significantly (approximately 37%) increased risk of post-transplant graft failure among explant-OHT procedures occurring at centers in the lowest volume quartile (HR = 1.371, 95% CI 1.030 to 1.825, p = 0.030). CONCLUSION Graft survival is decreased when performed at centers falling in the lowest quartile of LVAD explant-OHT for a given year. This volume-survival relationship should be considered in the context of limited donor organ availability and the rapidly growing number of LVAD centers.

Coronary sinus and atrioventricular groove avulsion after motor vehicle crash

Simultaneous cardiac and pericardial rupture from blunt chest trauma is a highly lethal combination with rarely reported survival. We report of a case of young patient with a right atrioventricular groove injury, pericardial rupture and a unique description of a coronary sinus avulsion following blunt chest trauma. Rapid recognition of this injury is crucial to patient survival, but traditional diagnostic adjuncts such as ultrasound, echocardiography and computed tomography are often unhelpful. Successful repair of these injuries requires high suspicion of injury, early cardiac surgery involvement of and possible even placement of the patient on cardiopulmonary bypass.