Tiziano Cassina

Preoperative diastolic function predicts the onset of left ventricular dysfunction following aortic valve replacement in high-risk patients with aortic stenosis

IntroductionLeft ventricular (LV) dysfunction frequently occurs after cardiac surgery, requiring inotropic treatment and/or mechanical circulatory support. In this study, we aimed to identify clinical, surgical and echocardiographic factors that are associated with LV dysfunction during weaning from cardiopulmonary bypass (CPB) in high-risk patients undergoing valve replacement for aortic stenosis.MethodsPerioperative data were prospectively collected in 108 surgical candidates with an expected operative mortality ≥9%. All anesthetic and surgical techniques were standardized. Reduced LV systolic function was defined by an ejection fraction <40%. Diastolic function of the LV was assessed using standard Doppler-derived parameters, tissue Doppler Imaging (TDI) and transmitral flow propagation velocity (Vp).ResultsDoppler-derived pulmonary flow indices and TDI could not be obtained in 14 patients. In the remaining 94 patients, poor systolic LV was documented in 14% (n = 12) and diastolic dysfunction in 84% of patients (n = 89), all of whom had Vp <50 cm/s. During weaning from CPB, 38 patients (40%) required inotropic and/or mechanical circulatory support. By multivariate regression analysis, we identified three independent predictors of LV systolic dysfunction: age (Odds ratio [OR] = 1.11; 95% confidence interval (CI), 1.01 to 1.22), aortic clamping time (OR = 1.04; 95% CI, 1.00 to 1.08) and Vp (OR = 0.65; 95% CI, 0.52 to 0.81). Among echocardiographic measurements, Vp was found to be superior in terms of prognostic value and reliability. The best cut-off value for Vp to predict LV dysfunction was 40 cm/s (sensitivity of 72% and specificity 94%). Patients who experienced LV dysfunction presented higher in-hospital mortality (18.4% vs. 3.6% in patients without LV dysfunction, P = 0.044) and an increased incidence of serious cardiac events (81.6 vs. 28.6%, P < 0.001).ConclusionsThis study provides the first evidence that, besides advanced age and prolonged myocardial ischemic time, LV diastolic dysfunction characterized by Vp ≤ 40 cm/sec identifies patients who will require cardiovascular support following valve replacement for aortic stenosis.

Clinical Review: Management of weaning from cardiopulmonary bypass after cardiac surgery

A sizable number of cardiac surgical patients are difficult to wean off cardiopulmonary bypass (CPB) as a result of structural or functional cardiac abnormalities, vasoplegic syndrome, or ventricular dysfunction. In these cases, therapeutic decisions have to be taken quickly for successful separation from CPB. Various crisis management scenarios can be anticipated which emphasizes the importance of basic knowledge in applied cardiovascular physiology, knowledge of pathophysiology of the surgical lesions as well as leadership, and communication between multiple team members in a high-stakes environment. Since the mid-90s, transoesophageal echocardiography has provided an opportunity to assess the completeness of surgery, to identify abnormal circulatory conditions, and to guide specific medical and surgical interventions. However, because of the lack of evidence-based guidelines, there is a large variability regarding the use of cardiovascular drugs and mechanical circulatory support at the time of weaning from the CPB. This review presents key features for risk stratification and risk modulation as well as a standardized physiological approach to achieve successful weaning from CPB.

Perioperative levosimendan in cardiac surgery: A systematic review with meta-analysis and trial sequential analysis

BACKGROUND Several studies suggested beneficial effects of perioperative levosimendan on postoperative outcome after cardiac surgery. However, three large randomized controlled trials (RCTs) have been recently published and presented neutral results. We performed a systematic review with meta-analysis and trial sequential analysis (TSA) to assess benefits and harms of perioperative levosimendan therapy in cardiac surgery. METHODS Electronic databases were searched up to September 2017 for RCTs on preoperative levosimendan versus any type of control. The Cochrane methodology was employed. We calculated odds ratio (OR) or Risk Ratio (OR) and 95% confidence interval (CI) using fixed-effects meta-analyses and we further performed TSA. RESULTS We included data from 40 RCTs and 4246 patients. Pooled analysis of 5 low risk of bias trials (1910 patients) showed no association between levosimendan and mortality (OR 0.86 [95% CI, 0.62, 1.18], p=0.34, TSA inconclusive), acute kidney injury, need of renal replacement therapy, myocardial infarction, ventricular arrhythmias, and serious adverse events, but an association with higher incidence of supraventricular arrhythmias (RR 1.11 [95% CI, 1.00, 1.24], p=0.05, TSA inconclusive) and hypotension (RR 1.15 [95% CI, 1.01, 1.30], p=0.04, TSA inconclusive). Analysis including all 40 trials found that levosimendan was associated with lower postoperative mortality (OR 0.56 [95% CI, 0.44, 0.71], p<0.00001, TSA conclusive), acute kidney injury, and renal replacement therapy, and higher incidence of hypotension. CONCLUSIONS There is not enough high-quality evidence to neither support nor discourage the systematic use of levosimendan in cardiac surgery.

Impact of anesthesia technique on the incidence of major complications after open aortic abdominal surgery: a cohort study

STUDY OBJECTIVE To determine the risk factors of perioperative complications and the impact of intrathecal morphine (ITM) in major vascular surgery. DESIGN Retrospective analysis of a prospective cohort. SETTINGS Operating room, intensive care unit, and Postanesthesia Care Unit of a university hospital. MEASUREMENTS Data from 595 consecutive patients who underwent open abdominal aortic surgery between January 1997 and December 2011 were reviewed. Data were stratified into three groups based on the analgesia technique delivered: systemic analgesia (Goup SA), thoracic epidural analgesia (Group TEA), and intrathecal morphine (Group ITM). Preoperative patient characteristics, perioperative anesthetic and medical interventions, and major nonsurgical complications were recorded. MAIN RESULTS Patients managed with ITM (n=248) and those given thoracic epidural analgesia (n=70) required lower doses of intravenous (IV) sufentanil intraoperatively and were extubated sooner than those who received systemic analgesia (n=270). Total inhospital mortality was 2.9%, and 24.4% of patients experienced at least one major complication during their hospital stay. Intrathecal morphine was associated with a lower risk of postoperative morbidity (OR 0.51, 95% CI 0.28 - 0.89), particularly pulmonary complications (OR 0.54, 95% CI 0.31 - 0.93) and renal dysfunction (OR 0.52, 95% CI 0.29 - 0.97). Other predictors of nonsurgical complications were ASA physical status 3 and 4 (OR 1.94, 95% CI 1.07 - 3.52), preoperative renal dysfunction (OR 1.61, 95% CI 1.01 - 2.58), prolonged surgical time (OR 1.78, 95% CI 1.16 - 2.78), and the need for blood transfusion (OR 1.77, 95% CI 1.05 - 2.99). CONCLUSIONS This single-center study showed a decreased risk of major nonsurgical complications in patients who received neuraxial analgesia after abdominal aortic surgery.

Goal-directed hemostatic therapy using the rotational thromboelastometry in patients requiring emergent cardiovascular surgery

AIMS AND OBJECTIVES We assessed the clinical impact of goal-directed coagulation management based on rotational thromboelastometry (ROTEM) in patients undergoing emergent cardiovascular surgical procedures. MATERIALS AND METHODS Over a 2-year period, data from 71 patients were collected prospectively and blood samples were obtained for coagulation testing. Administration of packed red blood cells (PRBC) and hemostatic products were guided by an algorithm using ROTEM-derived information and hemoglobin level. Based on the amount of PRBC transfused, two groups were considered: High bleeders (≥5 PRBC; HB) and low bleeders (<5 PRBC; LB). Data were analyzed using Chi-square test, unpaired t-test and analysis of variance as appropriate. RESULTS Pre-operatively, the HB group (n = 31) was characterized by lower blood fibrinogen and decreased clot amplitude at ROTEM compared with the LB group (n = 40). Intraoperatively, larger amounts of fibrinogen, fresh frozen plasma and platelets were required to normalize the coagulation parameters in the HB group. Post-operatively, the incidence of major thromboembolic and ischemic events did not differ between the two groups (<10%) and the observed in-hospital mortality was significantly less than expected by the Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (POSSUM score, 22% vs. 35% in HB and 5% vs. 13% in LB group). CONCLUSIONS ROTEM-derived information is helpful to detect early coagulation abnormalities and to monitor the response to hemostatic therapy. Early goal-directed management of coagulopathy may improve outcome after cardiovascular surgery.

Risk factors of postcardiotomy ventricular dysfunction in moderate-to-high risk patients undergoing open-heart surgery

Introduction: Ventricular dysfunction requiring inotropic support frequently occurs after cardiac surgery, and the associated low cardiac output syndrome largely contributes to postoperative death. We aimed to study the incidence and potential risk factors of postcardiotomy ventricular dysfunction (PCVD) in moderate-to-high risk patients scheduled for open-heart surgery. Methods: Over a 5-year period, we prospectively enrolled 295 consecutive patients undergoing valve replacement for severe aortic stenosis or coronary artery bypass surgery who presented with Bernstein-Parsonnet scores >7. The primary outcome was the occurrence of PCVD as defined by the need for sustained inotropic drug support and by transesophageal echography. The secondary outcomes included in-hospital mortality and the incidence of any major adverse events as well as Intensive Care Unit (ICU) and hospital length of stay. Results: The incidence of PCVD was 28.4%. Patients with PCVD experienced higher in-hospital mortality (12.6% vs. 0.6% in patients without PCVD) with a higher incidence of cardiopulmonary and renal complications as well as a prolonged stay in ICU (median + 2 days). Myocardial infarct occurred more frequently in patients with PCVD than in those without PCVD (19 [30.2%] vs. 12 [7.6%]). By logistic regression analysis, we identified four independent predictors of PCVD: left ventricular ejection fraction <40% (odds ratio [OR] = 6.36; 95% confidence interval [CI], 2.59–15.60), age older than 75 years (OR = 3.35; 95% CI, 1.64–6.81), prolonged aortic clamping time (OR = 3.72; 95% CI, 1.66–8.36), and perioperative bleeding (OR = 2.33; 95% CI, 1.01–5.41). The infusion of glucose-insulin-potassium was associated with lower risk of PCVD (OR = 0.14; 95% CI, 0.06–0.33). Conclusions: This cohort study indicates that age, preoperative ventricular function, myocardial ischemic time, and perioperative bleeding are predictors of PCVD which is associated with poor clinical outcome.

Hemodynamic challenge to early mobilization after cardiac surgery: A pilot study

Background: Active mobilization is a key component in fast-track surgical strategies. Following major surgery, clinicians are often reluctant to mobilize patients arguing that circulatory homeostasis would be impaired as a result of myocardial stunning, fluid shift, and autonomic dysfunction. Aims: We examined the feasibility and safety of a mobilization protocol 12-24 h after elective cardiac surgery. Setting and Design: This observational study was performed in a tertiary nonacademic cardiovascular Intensive Care Unit. Materials and Methods: Over a 6-month period, we prospectively evaluated the hemodynamic response to a two-staged mobilization procedure in 53 consecutive patients. Before, during, and after the mobilization, hemodynamics parameters were recorded, including the central venous oxygen saturation (ScvO 2 ), lactate concentrations, mean arterial pressure (MAP), heart rate (HR), right atrial pressure (RAP), and arterial oxygen saturation (SpO 2 ). Any adverse events were documented. Results: All patients successfully completed the mobilization procedure. Compared with the supine position, mobilization induced significant increases in arterial lactate (34.6% [31.6%, 47.6%], P = 0.0022) along with reduction in RAP (−33% [−21%, −45%], P < 0.0001) and ScvO 2 (−7.4% [−5.9%, −9.9%], P = 0.0002), whereas HR and SpO 2 were unchanged. Eighteen patients (34%) presented a decrease in MAP > 10% and nine of them (17%) required treatment. Hypotensive patients experienced a greater decrease in ScvO 2 (−18 ± 5% vs. −9 ± 4%, P = 0.004) with similar changes in RAP and HR. All hemodynamic parameters, but arterial lactate, recovered baseline values after resuming the horizontal position. Conclusions: Early mobilization after cardiac surgery appears to be a safe procedure as far as it is performed under close hemodynamic and clinical monitoring in an intensive care setting.

Randomized Evidence on Perioperative Statin Therapy in Cardiac Surgery

We very much appreciate the comments by Dr Rodriguez Cetina Biefer and colleagues [1] from Zurich regarding their experience and recommendations regarding the use of the Cor-Knot device for their minimally invasive mitral valve operations, in response to our article [2]. They described at least 2 patients found to have perforation of the anterior leaflet of the mitral valve by Cor-Knot devices, which led to moderate to severe mitral regurgitation, both of whom eventually underwent redo surgical procedures. The authors identify two possible causes of the leaflet perforation: angulation of the fasteners and use of flexible annuloplasty rings. They specifically wondered about the types of rings used in our case series and have not observed any additional cases of perforation since changing technique and ring type. In our case series, a semirigid 36-mm Medtronic CG complete ring with Cor-Knot fasteners was used for the original minimally invasive mitral valve repair performed at an outside hospital. During the redo operation we implanted a flexible 28-mm Cosgrove-Edwards incomplete ring using a 2-0 Ethibond annular mattress technique. We regularly use flexible, semirigid, and rigid incomplete and complete rings during our mitral operations, and we do not believe that the choice of ring should affect the propensity for Cor-Knot fasteners to result in perforation. When using the flexible Cosgrove-Edwards partial ring in both initial and redo mitral operations, we have not found this to result in fastener orientation toward the leaflets, and we have not observed a single case of this rare adverse event of leaflet perforation over hundreds of minimally invasive and redo mitral and tricuspid annuloplasty operations with the use of this ring. We believe that a wide variety of rings can be used with the Cor-Knot device and that the key to avoiding this adverse event remains devoting special consideration to needle angles and angulating the fasteners optimally. This rare adverse event is not a surgical device difficulty but rather a surgical technique problem.

Where Should I Send My Patient After the Operation

Thoracic surgery is associated with a high burden of perioperative morbidity and mortality. Fast tracking processes with timely recognition and treatment of complications favorably influence patient outcome. The level of postoperative monitoring and care needs to be adapted to patient’s illnesses and physiological reserves while considering procedural factors and any organ impairment associated with the surgical stress response. The use of dedicated risk scores may assist clinicians in planning patient admission in a postanesthesia care unit (PACU), a high dependency unit (HDU), or an intensive care unit (ICU). Until recently, a large proportion of patients undergoing high-risk thoracic interventions were routinely admitted in ICUs. Considering the advances of mini-invasive surgery and the favorable impact of perioperative organ protective strategies, an increasing number of these patients can be safely admitted to HDUs and PACUs, with no increase in postoperative complications. This cost-effective approach needs to be tailored to each hospital considering the available infrastructures and resources. Finally, thoracic surgeons, anesthesiologists, pneumologists, and intensivists need to develop close and confident partnerships aimed to implement evidence-based patient care, securing clinical pathways for thoracic surgical patient while promoting education, research, and innovations.