Preoperative Intraaortic Balloon Pump for Off-Pump Coronary Arterial Revascularization

Preoperative intra-aortic balloon pump improves the clinical outcomes of off-pump coronary artery bypass grafting in left ventricular dysfunction patients

Severe left ventricular (LV) dysfunction patients undergoing off-pump coronary artery bypass grafting (OPCAB) are often associated with a higher mortality. The efficacy and safety of the preoperative prophylactic intra-aortic balloon pump (IABP) insertion is not well established. 416 consecutive patients with severe LV dysfunction (ejection fraction ≤35%) undergoing isolated OPCAB were enrolled in a retrospective observational study. 191 patients was enrolled in the IABP group; the remaining 225 patients was in control group. A total of 129 pairs of patients were propensity-score matched. No significant differences in demographic and preoperative risk factors were found between the two groups. The postoperative 30-day mortality occurred more frequently in the control group compared with the IABP group (8.5% vs. 1.6%, p = 0.02). There was a significant reduction of low cardiac output syndrome in the IABP group compared with the control group (14% vs. 6.2%, p = 0.04). Prolonged mechanical ventilation (≥48 h) occurred more frequently in the control group (34.9% vs. 20.9%, p = 0.02). IABP also decreased the postoperative length of stay. Preoperative IABP was associated with a lower 30-day mortality, suggesting that it is effective in patients with severe LV dysfunction undergoing OPCAB.

Accuracy of Continuous Cardiac Output Measurement With the LiDCOplus System During Intra-Aortic Counterpulsation After Cardiac Surgery

OBJECTIVE

To evaluate the effect of intra-aortic counterpulsation on precision, accuracy, and concordance of continuous pulse contour cardiac output determined using LiDCOplus (LiDCO Group, London).

DESIGN

Prospective trial.

SETTING

University hospital critical care unit.

PARTICIPANTS

Patients with intra-aortic balloon pump support in the 1:1 mode after elective or urgent cardiac surgery.

INTERVENTIONS

Lithium dilution calibrated pulse contour cardiac output was compared with pulmonary artery bolus thermodilution cardiac output during hemodynamically stable conditions in the course of standardized postoperative management.

MEASUREMENTS AND MAIN RESULTS

Fifty-one paired measurements demonstrated good correlation between the 2 methods (r = 0.88, p<0.001). Mean bias was -0.14±0.81 L/min, limits of agreement 1.48 to -1.77 L/min, and percentage error 28%. Concordance between the 2 techniques regarding directional changes>±10% cardiac output was 100% (p = 0.008). Trending ability was moderate when paired cardiac output changes were assessed using linear regression, 4-quadrant table, and polar plots. When changes <±10% of the reference cardiac output were excluded, 90% of the data pairs still lay within the 30° radial limits. Optimal timing of the balloon pump was indispensable for proper determination of pulse contour cardiac output.

CONCLUSIONS

Because of the LiDCOplus-specific algorithm in determining stroke volume from the arterial pulse waveform, which differs from other devices, accuracy and precision of continuous pulse contour cardiac output only are affected insignificantly by intra-aortic counterpulsation. The authors nevertheless caution that the device should be recalibrated after major hemodynamic alterations or otherwise inexplicable changes of the pulse contour cardiac output to improve trending.

Outcome Reporting in Cardiac Surgery Trials: Systematic Review and Critical Appraisal

Background

There is currently no accepted standard for reporting outcomes following cardiac surgery. The objective of this paper was to systematically review the literature to evaluate the current use and definition of perioperative outcomes reported in cardiac surgery trials.

Methods and Results

We reviewed 5 prominent medical and surgical journals on Medline from January 1, 2010, to June 30, 2014, for randomized controlled trials involving coronary artery bypass grafting and/or valve surgery. We identified 34 trials meeting inclusion criteria. Sample sizes ranged from 57 to 4752 participants (median 351). Composite end points were used as a primary outcome in 56% (n=19) of the randomized controlled trials and as a secondary outcome in 12% (n=4). There were 14 different composite end points. Mortality at any time (all-cause and/or cardiovascular) was reported as an individual end point or as part of a combined end point in 82% (n=28), myocardial infarction was reported in 68% (n=23), and bleeding was reported in 24% (n=8). Patient-centered outcomes, such as quality of life and functional classification, were reported in 29% (n=10). Definition of clinical events such as myocardial infarction, stroke, renal failure, and bleeding varied considerably among trials, particularly for postoperative myocardial infarction and bleeding, for which 8 different definitions were used for each.

Conclusions

Outcome reporting in the cardiac surgery literature is heterogeneous, and efforts should be made to standardize the outcomes reported and the definitions used to ascertain them. The development of standardizing outcome reporting is an essential step toward strengthening the process of evidence-based care in cardiac surgery.

Preoperative intra-aortic counterpulsation in high-risk patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials†

In contrast to the results of previous studies, recent randomized controlled trials (RCTs) failed to show a benefit of prophylactic aortic counterpulsation in high-risk patients undergoing cardiac surgery. The present analysis aims to redefine the effects of this treatment modality in the light of this new evidence. MEDLINE, EMBASE, CENTRAL/CCTR, Google Scholar and reference lists of relevant articles were searched for full-text articles of RCTs in English or German. Assessments for eligibility, relevance, study validity and data extraction were performed by two reviewers independently using prespecified criteria. The primary outcome was hospital mortality. A total of nine eligible RCTs with 1171 patients were identified: 577 patients were treated preoperatively with intra-aortic balloon pump (IABP) and 594 patients served as controls. The pooled odds ratio (OR) for hospital mortality (22 hospital deaths in the intervention arm, 54 in the control group) was 0.381 (95% CI 0.230-0.629; P < 0.001). The pooled analyses of five RCTs including only patients undergoing isolated on-pump coronary artery bypass grafting (n[IABP] = 348, n[control] = 347) also showed a statistically significant improvement in mortality for preoperative IABP implantation (fixed-effects model: OR 0.267, 95% CI 0.129-0.552, P < 0.001). The pooled OR for hospital mortality from two randomized off-pump trials was 0.556 (fixed-effects model, 95% CI 0.207-1.493, P = 0.226). Preoperative aortic counterpulsation was associated with a significant reduction in low cardiac output syndrome (LCOS) in the total population (fixed-effects model: OR 0.330, 95% CI 0.214-0.508, P < 0.001) as well as in the subgroup of CAGB patients (fixed-effects model: OR 0.113, 95% CI 0.056-0.226, P < 0.001), whereas there was no benefit in the off-pump population (fixed-effects model: OR 0.555, 95% CI 0.209-1.474, P = 0.238). Preoperative IABP implantation was associated with a reduction of intensive care unit (ICU) stay in all investigated populations with a greater effect in the total population [fixed-effects model: standard mean difference (SMD) -0.931 ± 0.198, P < 0.001] as well as in the subgroup of CAGB patients (fixed-effects model: SMD -1.240 ± 0.156, P < 0.001), compared with the off-pump group (fixed-effects model: SMD -0.723 ± 0.128, P < 0.001). Despite contradictory results from recent trials, the present study confirms the findings of previous meta-analyses that prophylactic aortic counterpulsation reduces hospital mortality, incidence of LCOS and ICU requirement in high-risk patients undergoing on-pump cardiac surgery. However, owing to small sample sizes and the lack of a clear-cut definition of high-risk patients, an adequately powered, prospective RCT is necessary to find a definite answer to the question, if certain groups of patients undergoing cardiac surgery benefit from a prophylactic IABP insertion.

Multiple composite grafts (k, π or double-Y) in coronary artery surgery: a choice or a necessity?

OBJECTIVES

Composite grafts allow complete arterial revascularization with minimal aortic manipulations. The Y-T configuration supplies all distal branches adequately, whereas it is unclear whether complex composite configurations (K, Π or double-Y) are equally at rest or when challenged by maximal requirements.

METHODS

Forty-seven patients who underwent off-pump coronary artery revascularization by multiple arterial composite grafts (K, Π or double-Y) were retrospectively evaluated. Indication for this surgical option was porcelain aorta or conduit unavailability. Composite systems were evaluated by intraoperative flow measurements and perioperative transthoracic Doppler ultrasonography, 12 months later also by exercise test, sestamibi scintigraphy at rest and during induced hyperaemia and by 64-slice multidetector CT angiography.

RESULTS

A total of 141 distal anastomoses were implanted as composite grafts. Perioperative flow measurements and 12-month Doppler ultrasonography were adequate at rest. At stress test, chest pain and/or induced ECG evidence of ischaemia are found in 16 patients (39%). During dipyridamole-induced hyperaemia, single-photon emission computed tomography image revealed that mean summed stress score was 7.2 ± 5.7, summed difference score 5.3 ± 4.2 and coronary flow reserve 1.7 ± 0.2.

CONCLUSIONS

Multiple composite grafts, albeit adequate at rest, were unable to meet flow requirements during maximal hyperaemia. In daily practice, their use must be not a choice but rather a necessity in those patients without alternative options.

Intraaortic balloon pump boon for off-pump coronary artery bypass grafting

Background

Off-pump coronary artery bypass techniques have evolved in the past decade, but there are some concerns about hemodynamic decompensation requiring conversion to cardiopulmonary bypass. These conversions are associated with higher morbidity and mortality. We use an intraaortic balloon pump to treat ischemia-induced hemodynamic instability and arrhythmias during off-pump coronary artery bypass. The objective of this study was to assess the impact of intraaortic balloon pump use in off-pump coronary artery bypass to prevent emergency conversion to cardiopulmonary bypass.

Methods

Data of 529 consecutive unselected patients who underwent isolated coronary artery bypass were included in this retrospective study of prospectively collected data and operation notes. Complete revascularization was performed using an off-pump technique. All arterial grafts using bilateral internal mammary arteries, and aortic no-touch technique were preferred. If the clinical situation demanded, vein grafts were used. During the procedure, any hemodynamic compromise not responding to conventional inotropic therapy was treated with intraaortic balloon pump insertion.

Results

Complete revascularization was possible in all 529 patients. An intraaortic balloon pump was inserted in 33 (6.2%) patients to treat hemodynamic instability; in all cases, conversion to cardiopulmonary bypass was avoided and complete revascularization was achieved.

Conclusion

For treating hemodynamic instability during off-pump coronary artery bypass, we recommend intraaortic balloon pump insertion as the preferred bail-out method rather than conversion to cardiopulmonary bypass.

Continuative statin therapy after percutaneous coronary intervention improves outcome in coronary bypass surgery: a propensity score analysis of 2501 patients

OBJECTIVES

A history of percutaneous coronary intervention increases the risk of death and complications of coronary artery bypass grafting. This retrospective multicenter study evaluated the impact of continuative use of statin on postoperative outcomes when subsequent elective coronary artery bypass grafting is required after percutaneous coronary intervention.

METHODS

Among 14,575 patients who underwent isolated first-time coronary artery bypass grafting between January 2000 and December 2010, 2501 who had previous percutaneous coronary intervention with stenting and fulfilled inclusion criteria were enrolled. Continuative statin therapy was used in 1528 patients and not used in 973 patients. Logistic multiple regression and propensity score analyses were used to assess the risk-adjusted impact of statin therapy on in-hospital mortality and major adverse cardiac events. The Cox proportional hazards model was constructed to assess the effect of continuative statin therapy on 24-month outcome.

RESULTS

At multivariate analysis, age more than 70 years, 3-vessel or 2-vessel plus left main coronary disease, multivessel percutaneous coronary intervention, ejection fraction 0.40 or less, diabetes mellitus, and logistic European System for Cardiac Operative Risk Evaluation 5 or greater were independent predictors of hospital mortality and major adverse cardiac events. After propensity score matching, conditional logistic regression analysis demonstrated that continuative statin therapy before coronary artery bypass grafting reduced the risk for hospital and 2-year mortality (odds ratio [OR], 0.27; 95% confidence interval [CI], 0.12-0. 57; P=.004 and OR, 0.6; 95% CI, 0.36-0.96; P=.04, respectively) and major adverse cardiac events (OR, 0.31; 95% CI, 0.18-0.78; P=.003 and OR, 0.5; 95% CI, 0.34-0.76; P=.006, respectively).

CONCLUSIONS

Long-term statin treatment after percutaneous coronary intervention improves early and midterm outcome when surgical revascularization will be required.

The year in cardiothoracic and vascular anesthesia: selected highlights from 2012

Cardiothoracic and vascular critical care has emerged as a subspecialty due to procedural breakthroughs, an aging population, and a multidisciplinary collaboration. This subspecialty now has a dedicated professional society, recently published guidelines, and plans for standardized certification. This paradigm shift represents a major collaboration opportunity for our specialty. The rise of evidence-based perioperative practice has produced a culture of large trials in our specialty to search for solutions to the challenging outcome questions. Besides the growth in the development of evidence, the consensus conference format and postpublication peer review have both emerged as effective processes for identifying the most relevant high-quality evidence. The quest for best perioperative practice has highlighted the importance of teamwork at all phases of care with respect to transitions in care, blood component transfusion, and research misconduct. The emergence of ultrasound as a standard for central vascular access also has been emphasized in recent multisociety guidelines. There also has been a paradigm shift in the management of patients with coronary artery disease. Recent guidelines have emphasized the roles of the cardiac anesthesiologist and the interventional cardiologist as part of the heart team approach. Major recent trials in comparative effectiveness have challenged the advantages of percutaneous coronary intervention, off-pump coronary artery bypass surgery, and intra-aortic balloon counterpulsation. The year 2012 has witnessed the emergence of new paradigms of care in our specialty with the emphasis on teamwork, safety, and quality. These processes will further improve perioperative outcome.