Minimally Invasive Mitral Valve Surgery I: Patient Selection, Evaluation, and Planning.

Widespread adoption of minimally invasive mitral valve repair and replacement may be fostered by practice consensus and standardization. This expert opinion, first of a 3-part series, outlines current best practices in patient evaluation and selection for minimally invasive mitral valve procedures, and discusses preoperative planning for cannulation and myocardial protection.

Minimally Invasive Mitral Valve Surgery II: Surgical Technique and Postoperative Management.

Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery.

Minimally Invasive Mitral Valve Surgery III: Training and Robotic-Assisted Approaches.

Minimally invasive mitral valve operations are increasingly common in the United States, but robotic-assisted approaches have not been widely adopted for a variety of reasons. This expert opinion reviews the state of the art and defines best practices, training, and techniques for developing a successful robotics program.

Inhaled Nitric Oxide Augments Left Ventricular Assist Device Capacity by Ameliorating Secondary Right Ventricular Failure.

Clinical right ventricular (RV) impairment can occur with left ventricular assist device (LVAD) use, thereby compromising the therapeutic effectiveness. The underlying mechanism of this RV failure may be related to induced abnormalities of septal wall motion, RV distension and ischemia, decreased LV filling, and aberrations of LVAD flow. Inhaled nitric oxide (NO), a potent pulmonary vasodilator, may reduce RV afterload, and thereby increase LV filling, LVAD flow, and cardiac output (CO). To investigate the mechanisms associated with LVAD-induced RV dysfunction and its treatment, we created a swine model of hypoxia-induced pulmonary hypertension and acute LVAD-induced RV failure and assessed the physiological effects of NO. Increased LVAD speed resulted in linear increases in LVAD flow until pulse pressure narrowed. Higher speeds induced flow instability, LV collapse, a precipitous fall of both LVAD flow and CO. Nitric oxide (20 ppm) treatment significantly increased the maximal achievable LVAD speed, LVAD flow, CO, and LV diameter. Nitric oxide resulted in decreased pulmonary vascular resistance and RV distension, increased RV ejection, promoted LV filling and improved LVAD performance. Inhaled NO may thus have broad utility for the management of biventricular disease managed by LVAD implantation through the effects of NO on LV and RV wall dynamics.

Incremental value of the preoperative echocardiogram to predict mortality and major morbidity in coronary artery bypass surgery.

BACKGROUND: Although echocardiography is commonly performed before coronary artery bypass surgery, there has yet to be a study examining the incremental prognostic value of a complete echocardiogram. METHODS AND RESULTS: Patients undergoing isolated coronary artery bypass surgery at 2 hospitals were divided into derivation and validation cohorts. A panel of quantitative echocardiographic parameters was measured. Clinical variables were extracted from the Society of Thoracic Surgeons database. The primary outcome was in-hospital mortality or major morbidity, and the secondary outcome was long-term all-cause mortality. The derivation cohort consisted of 667 patients with a mean age of 67.2±11.1 years and 22.8% females. The following echocardiographic parameters were found to be optimal predictors of mortality or major morbidity: severe diastolic dysfunction, as evidenced by restrictive filling (odds ratio, 2.96; 95% confidence interval, 1.59-5.49), right ventricular dysfunction, as evidenced by fractional area change <35% (odds ratio, 3.03; 95% confidence interval, 1.28-7.20), or myocardial performance index >0.40 (odds ratio, 1.89; 95% confidence interval, 1.13-3.15). These results were confirmed in the validation cohort of 187 patients. When added to the Society of Thoracic Surgeons risk score, the echocardiographic parameters resulted in a net improvement in model discrimination and reclassification with a change in c-statistic from 0.68 to 0.73 and an integrated discrimination improvement of 5.9% (95% confidence interval, 2.8%-8.9%). In the Cox proportional hazards model, right ventricular dysfunction and pulmonary hypertension were independently predictive of mortality over 3.2 years of follow-up. CONCLUSIONS: Preoperative echocardiography, in particular right ventricular dysfunction and restrictive left ventricular filling, provides incremental prognostic value in identifying patients at higher risk of mortality or major morbidity after coronary artery bypass surgery.

Aortic sclerosis is associated with mortality and major morbidity in patients undergoing coronary artery bypass surgery.

OBJECTIVE: In this study, we aim to investigate the association between aortic sclerosis and mortality and major morbidity in patients with established coronary artery disease undergoing coronary artery bypass grafting (CABG). DESIGN: Preoperative echocardiograms of consecutive patients undergoing isolated CABG between 2007 and 2009 (n=1150) were analysed, excluding patients without an echocardiogram in the 30 days prior to surgery (n=483). Using logistic regression, we evaluated the association between aortic sclerosis and inhospital mortality and major morbidity. Using Cox proportional hazards, the effect on long-term all-cause mortality was determined. SETTING: Massachusetts General Hospital, Boston. PATIENTS: Patients undergoing isolated CABG between 2007 and 2009. INTERVENTIONS: Analysis of echocardiograms. MAIN OUTCOME MEASURES: Inhospital mortality and major morbidity, and long-term all-cause mortality. RESULTS: 627 patients were suitable for enrolment; 207 (33%) had significant aortic sclerosis. These patients had higher rates of traditional cardiovascular risk factors. Significant aortic sclerosis was associated with an increased risk of inhospital mortality or major morbidity (OR 1.95; 95% CI 1.25 to 3.04). Following adjustment for baseline clinical and echocardiographic variables, the association remained significant (OR 1.90; 95% CI 1.15 to 3.11). The HR for adjusted all-cause mortality was 2.52 (mean follow-up 2.7 years). CONCLUSIONS: Aortic sclerosis is a common finding in patients undergoing CABG. In these patients, its presence is associated with a higher risk of inhospital mortality or major morbidity, and is associated with a higher risk of all-cause long-term mortality independent of other risk factors.

Educational program in crisis management for cardiac surgery teams including high realism simulation.

INTRODUCTION: Cardiac surgery demands effective teamwork for safe, high-quality care. The objective of this pilot study was to develop a comprehensive program to sharpen performance of experienced cardiac surgical teams in acute crisis management. METHODS: We developed and implemented an educational program for cardiac surgery based on high realism acute crisis simulation scenarios and interactive whole-unit workshop. The impact of these interventions was assessed with postintervention questionnaires, preintervention and 6-month postintervention surveys, and structured interviews. RESULTS: The realism of the acute crisis simulation scenarios gradually improved; most participants rated both the simulation and whole-unit workshop as very good or excellent. Repeat simulation training was recommended every 6 to 12 months by 82% of the participants. Participants of the interactive workshop identified 2 areas of highest priority: encouraging speaking up about critical information and interprofessional information sharing. They also stressed the importance of briefings, early communication of surgical plan, knowing members of the team, and continued simulation for practice. The pre/post survey response rates were 70% (55/79) and 66% (52/79), respectively. The concept of working as a team improved between surveys (P = .028), with a trend for improvement in gaining common understanding of the plan before a procedure (P = .075) and appropriate resolution of disagreements (P = .092). Interviewees reported that the training had a positive effect on their personal behaviors and patient care, including speaking up more readily and communicating more clearly. CONCLUSIONS: Comprehensive team training using simulation and a whole-unit interactive workshop can be successfully deployed for experienced cardiac surgery teams with demonstrable benefits in participant's perception of team performance.

Quadricuspid aortic valve: a report of 12 cases and a review of the literature.

Quadricuspid aortic valve (QAV) is rare and its diagnosis, clinical course, and management are less well defined relative to other aortic valve abnormalities. Advances in diagnostic imaging, notably in ultrasound, have increased clinical awareness of this anomaly and prompted this review of our experience with 12 new patients and a compilation of previously reported patients to further characterize this condition.

Consumer comprehension of surgeon performance data for coronary bypass procedures.

BACKGROUND: Public and private organizations have called for increased transparency in reporting of outcomes data for hospitals and surgeons, including risk-adjusted coronary artery bypass graft surgery (CABG) mortality data. Limited information is available about how the public actually interprets these data. METHODS: Four different graphical and tabular displays of CABG outcomes for surgeons, three of which were modeled on current state public reports, were shown to 337 adults. Each display contained data for 3 to 5 hypothetical surgeons. For each format, respondents were asked to choose which surgeon they would be most and least likely to choose based on the data. Additionally, they were asked questions about public reporting. RESULTS: Accurate identification of best surgeon performance varied by display format, with a high of 66% on one display and a low of 16% on another. Only 6.4% identified the surgeon with the lowest risk mortality across all four displays. Respondents with at least some college education were significantly more likely to identify the surgeon with the lowest risk-adjusted mortality, compared with respondents having no college education (21% to 72% vs. 9% to 59%; p<0.01). In one display, the surgeon with the lowest risk-adjusted mortality was effectively penalized for taking on higher-risk patients; respondents tended to select the surgeon with the lowest-risk population but the highest risk-adjusted mortality. Overall, 82% of respondents said that access to these types of data would be "absolutely essential" or "very important" in choosing a surgeon. CONCLUSIONS: Comprehension by the public of risk-adjusted CABG outcomes is limited and varies by display format. Poorly constructed displays may have led to misinterpretation, with potential unintended adverse consequences such as risk aversion. Further work is needed to design displays that maximize accurate interpretation by the public and more clearly define the risk and benefit of public reporting of surgeon performance.

Coronary artery bypass grafting after recent or remote percutaneous coronary intervention in the Commonwealth of Massachusetts.

BACKGROUND: In this study, we sought to characterize the outcomes after isolated coronary artery bypass grafting (CABG) in patients with a history of remote (≥14 days), and recent (<14 days), percutaneous coronary intervention (PCI). METHODS AND RESULTS: Patients with PCI within 5 years of CABG were identified among 12 591 primary isolated CABG reported in the mandatory Massachusetts Adult Cardiac Surgery Database. Patients were excluded if they were out-of-state (n=1043, 8%), had undergone primary PCI for acute myocardial infarction (n=401, 3%), had a PCI-CABG interval >5 years or unknown (n=136 and n=673, 1% and 5%). Patients with a history of remote and recent PCI were analyzed separately. Each CABG patient with PCI was matched to 3 patients without PCI using a propensity score. Outcomes were analyzed using generalized estimating equations and stratified proportional hazards models, with a mean follow-up of 4.1±1.2 years. There were 1117 CABG patients (9%) with prior PCI (n(remote)=823; n(recent)=294). In matched CABG patients with remote prior PCI, no differences were found in 30-day mortality (1.1% versus 1.5%; P=0.432), hospital morbidity (41% versus 40%; P=0.385) and overall survival (hazard ratio, [95% confidence interval] for death for prior PCI, 0.93 [0.74 to 1.18]; P=0.555). In matched CABG patients with recent prior PCI, hospital morbidity was higher (59% versus 45%; P<0.001), but no differences were found in 30-day mortality (3.5% versus 3.1%; P=0.754) and overall survival (HR, 1.18 [0.83 to 1.69]; P=0.353). CONCLUSIONS: In patients undergoing CABG, remote prior PCI (≥14 days) was not associated with adverse outcomes at 30 days or during long-term follow-up.

Financial consequences of implementing a partner-in-care in cardiac surgery.

BACKGROUND: In 2003, a satellite cardiac surgery program (SAT) was implemented at an affiliated community hospital located in an area historically served by an academic medical center (AMC). This study assessed the financial consequences and the changes in case-mix that occurred at the AMC after SAT implementation. METHODS: From June 2002 through December 2005, 4593 adult patients underwent cardiac operations at the AMC. Excluded were 400 patients operated on during the 4-month transition period after SAT implementation and 1210 patients living more than 35 miles from the AMC. Multivariable regression was used to compare changes in case-mix and propensity-score adjusted costs for AMC patients referred from SAT area (N(before/after =) 328/291) vs other patients (N(before/after =) 897/1467). RESULTS: The SAT area referral rate decreased by 55%. Compared with other patients, AMC patients referred from the SAT area showed a greater increase in age in the second period (p = 0.013). The nursing workload and adjusted mean costs increased more for patients from the SAT area (p = 0.015 and 0.014, respectively). The hospital margin decreased in the second period for both referral areas (p < 0.001). For the patient subgroup undergoing coronary artery bypass grafting, this hospital margin decrease was greater for SAT area patients (p = 0.017). CONCLUSIONS: After implementation of SAT program, fewer patients of lower complexity came to the AMC from the SAT area, and there was a significant increase in nursing workload and costs. During this interval, hospital margin for cardiac operations decreased from both referral areas but decreased significantly more for coronary artery bypass graft patients from the SAT area.

Aortic dissection and moyamoya disease in Turner syndrome.

Aortic dilation and dissection are well-recognized cardiac abnormalities in women with Turner syndrome (TS), although the underlying pathophysiology is not fully understood. We report on a 46-year-old Hispanic woman who was previously diagnosed with moyamoya disease on magnetic resonance imaging after a presentation with stroke-like symptoms. Her features were consistent with TS and chromosome analysis revealed mosaicism in which 17% of the cells showed a pseudoisodicentric Y chromosome: 45,X (25)/46,X psu idic (Y)(11.2) (5). A preceding screening transthoracic echocardiogram had shown a bicuspid aortic valve (BAV) with an aortic diameter of 3.2 cm; at the time of moyamoya diagnosis, the aorta was 3.5 cm with mild aortic stenosis and mild aortic regurgitation. Four years later, the patient had had an acute aortic dissection, Stanford type A, which was repaired successfully. This case report is the third individual with TS associated with moyamoya disease and the first associated with dissection. The small number of cases does not allow detailed analysis other than noting patient age (two older than 40 years), karyotype (two others associated with isochrome Xq), and associated cardiac risk factors (one with BAV). Although this may be a chance occurrence, we hypothesize that moyamoya disease could be a manifestation of the vasculopathy in TS.

Diagnosis of congenital unicuspid aortic valve in adult population: the value and limitation of transesophageal echocardiography.

BACKGROUND: This study aimed to assess the accuracy of two-dimensional echocardiography (echo) in diagnosing unicuspid aortic valve (UAV) and to determine echo features that could improve the diagnosis. METHOD: We reviewed transthoracic/transesophageal echoes (TTE/TEE) from our hospital database for adult patients who had aortic valve surgery with a preoperative echo diagnosis of UAV or equivocal diagnosis of bicuspid aortic valve (BAV) BAV/UAV. Morphological characteristics of AV and ascending aortic dimensions were evaluated. RESULTS: Nineteen patients were identified, 13 (11 Male, 2 Female, mean age 47 ± 10 years) had surgically confirmed diagnosis of UAV, six had BAV. The incidence of UAV was 2.6%. For diagnosing UAV, the sensitivity and specificity of TTE was 27% and 50% and those of TEE was 75% and 86%, respectively. For TTE, positive predictive value (PPV) was 60% and negative predictive value (NPV) was 20%. By TEE, PPV was 90% and the NPV was 67%. In UAV patients, 85% had severe aortic stenosis (mean gradient 45 ± 16 mmHg, AVA: 0.9 ± 0.2 cm²). 46% had ascending aorta aneurysm (mean aortic root, sinutubular junction, ascending aorta dimensions: 36 ± 3 mm, 31 ± 4 mm and 41 ± 8 mm). Patients with ascending aortic aneurysm were younger (41 ± 11 years vs. 52 ± 5 years, P < 0.05) All UAV were unicommissural with a posteriorly positioned commissural attachment, 69% were heavily calcified. Diagnostic accuracy was limited by quality of images, severity, and distribution of calcification. CONCLUSION: TEE is the diagnostic modality of choice in UAV. Identifying several echo features may improve its diagnostic accuracy.

Safety and efficacy of the argatroban therapy during the early post-cardiac surgery period.

Heparin-induced thrombocytopenia (HIT) is associated with a high incidence of vein graft occlusion after cardiac surgery. When HIT is suspected during the post-operative period, current guideline recommends a direct thrombin inhibitor such as argatroban to be started immediately. The aim of this retrospective study was to evaluate the safety and efficacy of argatroban in the early period after cardiac surgery. All patients who received argatroban within 72 h after cardiac surgery from September 2005 to June 2009 from a single center were included. Patient demographics, pre-operative relevant history, intra-operative events and post-operative data were collected and analyzed. The primary endpoints were bleeding, thrombotic complication during or after argatroban administration, and in-hospital mortality. The study population comprised 31 patients administered argatroban within 72 h after cardiac surgery. Argatroban was started a mean of 1.7 days after surgery (median dose, 0.66 µg/kg/min; median duration, 5.9 days). Twenty patients (64.5%) experienced bleeding; episode driven entirely by the need for blood transfusion. No new thromboembolic complication occurred during or after argatroban infusion. One patient died from aspiration pneumonia. Compared to those without bleeding complications, patients who bled had longer operation times and increased use of intra-aortic balloon pump. However, argatroban therapy including the starting time, median dose, infusion duration, and activated partial thromboplastin times showed no difference between the two groups. In cardiac surgery patients with clinical suspicion of HIT, early postoperative use of argatroban seems well-tolerated and associated with a low risk of thrombotic events.

Surgical management and long-term outcomes for acute ascending aortic dissection.

OBJECTIVE: We sought to assess early and late survival and cardiovascular-specific mortality after surgical repair of acute ascending aortic dissection and the effect of differences in surgical technique, patient characteristics, and preoperative diagnostic testing. METHODS: Between 1979 and 2003, 195 consecutive patients underwent repair for acute ascending aortic dissection within 2 weeks of the onset of symptoms. Mean follow-up was 7.0 +/- 5.9 years (range, 0-26 years) and was 100% complete. RESULTS: Patients were aged 62 +/- 15 years on average and were mostly male (66%) and hypertensive (69%). Risk of death early and late after the operation decreased over the study period, with hospital mortality decreasing from 21% to 4% when comparing the first and most recent quartiles (P = .007, chi(2) test for trend). At 1, 5, 10, and 20 years postoperatively, survival was 84%, 69%, 55%, and 30%, respectively, and freedom from cardiovascular death was 86%, 80%, 71%, and 51%, respectively. Additional independent risk factors for death were older age (P < .001), renal dysfunction (P < .003), syncope (P = .007), and peripheral vascular disease (P = .006). During the study period, echocardiographic and computed tomographic diagnostic imaging replaced routine aortic angiographic analysis, and operative techniques involved more frequent use of open distal anastomoses, retrograde cerebral perfusion, earlier restoration of antegrade perfusion, and a conservative approach to aortic arch repair. Freedom from reoperation on the aorta or aortic valve was 93% and 84% at 5 and 10 years, respectively. CONCLUSIONS: Early and late survival after repair of acute ascending aortic dissection has improved progressively over 25 years in association with noticeable changes in preoperative and intraoperative management. Aortic reoperations were infrequent during follow-up.

Prospective, comprehensive assessment of cardiac troponin T testing after coronary artery bypass graft surgery.

BACKGROUND: The significance and clinical role of cardiac troponin testing after coronary artery bypass grafting remain unclear. METHODS AND RESULTS: Cardiac troponin T (cTnT) was measured during the first 24 hours after coronary artery bypass graft surgery in 847 consecutive patients. Only 17 patients (2.0%) had new Q waves or left bundle-branch block after surgery; however, cTnT elevation was observed in nearly all subjects, with a median cTnT concentration of 1.08 ng/mL overall. Direct predictors of postoperative cTnT values included preoperative myocardial infarction (P<0.001), preoperative intraaortic balloon pump (P<0.001), intraoperative/postoperative intraaortic balloon pump (P<0.001), number of distal anastomoses (P=0.005), bypass time (P<0.001), and number of intraoperative defibrillations (P=0.009), whereas glomerular filtration rate (P<0.001), off-pump coronary artery bypass grafting (P=0.003), and use of warm cardioplegia (P=0.02) were inversely associated with cTnT values. A linear association was seen between cTnT levels and length of stay and ventilator hours, and in an analysis adjusted for the Society for Thoracic Surgery Risk Model, cTnT remained independently prognostic for death (odds ratio, 3.20; P=0.003), death or heart failure (odds ratio, 2.04; P=0.008), death or need for vasopressors (odds ratio, 2.70; P<0.001), and the composite of all 3 (odds ratio, 2.57; P<0.001). In contrast to consensus-endorsed cTnT cut points for postoperative evaluation, a cTnT <1.60 ng/mL had a negative predictive value of 93% to 99% for excluding various post-coronary artery bypass graft surgery complications. CONCLUSIONS: cTnT concentrations after coronary artery bypass graft surgery are nearly universally elevated, are determined by numerous factors, and are independently prognostic for impending postoperative complications when used at appropriate cut points.

Funnel-tipped aortic cannula for reduction of atheroemboli.

BACKGROUND: Atheroemboli caused by aortic manipulation poses a risk for stroke in patients undergoing cardiopulmonary bypass (CPB) surgery. One potential cause is the high velocity jet from aortic perfusion cannulae. This study describes the flow patterns of a novel funnel-tip cannula designed to reduce emboli by decreasing fluid velocity and resultant shear force on the aortic wall. METHODS: A funnel-tip cannula was constructed and compared with standard straight-tip cannulae and the Dispersion (Research Medical Inc, Midvale, UT) and Sarns Soft Flow (Terumo Cardiovascular Systems Corp, Ann Arbor, MI) cannulae. Pressure drop measurements were collected at 1 to 6 L/minute flows. Velocity flow profiles were created using phase contrast magnetic resonance imaging. Absolute velocity was measured in a phantom aorta at 5 L/minute flow. Each cannula was further studied in a synthetic model of an atherosclerotic aorta to determine the mass of dislodged particulate matter generated at 2, 3, and 5 L/minute flows. RESULTS: The funnel-tip cannula demonstrated significantly lower values (p < 0.05) in pressure drop (55 mm Hg), exit velocity (309 cm/second, 167 cm/second for center axis and wall, respectively), and particulate dislodgement (0.15 +/- 0.05 g) than other tested cannulae. The Soft Flow cannula generated the next lowest pressure drop but exhibited twice the exit velocity and particulate dislodgement of the funnel-tip cannula. The Dispersion cannula did not demonstrate a reduction in velocity or particulate dislodgement compared with the standard straight-tip cannulae. CONCLUSIONS: The results of this study suggest that a low-angled funnel-tip cannula has favorable flow characteristics warranting further investigation. Design development may reduce the risk of atheroemboli generation during CPB surgery.