Reduced Mortality in High-Risk Coronary Patients Operated Off Pump With Preoperative Intraaortic Balloon Counterpulsation

Long-term impact of critical silent cerebrovascular disease in patients undergoing coronary artery bypass surgery: a propensity score and multivariate analyses

BACKGROUND

Cerebrovascular disease (CVD) with brain hypoperfusion is a strong risk factor for stroke. However, how this pathology influences long-term outcomes after coronary artery bypass graft (CABG) surgery is not known.

METHODS

Magnetic resonance imaging/angiography (MRI/A) of the neck and brain was performed in 318 out of 575 consecutive CABG patients between May 2005 and April 2018. Critical CVD with chronic hypoperfusion was defined as multiple severe stenoses (⩾70%) and/or occlusion in the carotid and/or vertebral systems associated with reduced collateral flow due to severe contralateral and/or circle of Willis lesion. Fifty patients were identified to have this pathology (early results were previously reported). The entire cohort was followed up for 83.6 ± 53.7 months. Carotid endarterectomy was considered for symptomatic patients. Propensity matching was performed to compare long-term outcomes between patients with and without critical CVD.

RESULTS

Patients with critical CVD at follow-up displayed significantly higher incidences of stroke than those without critical CVD (p=0.007), with an extremely high final incidence (approximately 40% at 8 years). However, survival (p=0.623) and incidences of major adverse cardiac events (MACE: myocardial infarction, coronary revascularization and all causes of death) (p=0.881) were similar. The Cox hazard model revealed that critical CVD was the strongest risk factor for stroke (p=0.000; hazard ratio 6.572; 95% confidence interval 2.657-16.258) while not affecting survival and MACE.

CONCLUSION

Critical CVD was the strongest risk factor for long-term stroke after CABG. However, survival and MACE-free rates were equivalent in patients with critical CVD and those without critical CVD.

Clinical application of intra-aortic balloon counterpulsation in high-risk patients undergoing cardiac surgery

The intra-aortic balloon pump (IABP) has been the most commonly used mechanical circulatory support device for nearly five decades. In theory, the IABP can increase the blood and oxygen supply of the coronary artery by increasing the diastolic pressure in the aortic root when the balloon is inflated and reduce left ventricular afterload by rapidly deflating the balloon during the systolic phase. Therefore, some researchers put forward the idea of preoperative prophylactic use of an IABP, which has been frequently performed in high-risk patients undergoing elective percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG). Previous studies have suggested preoperative IABP has a controversial effect on patients undergoing revascularization; the role of preoperative IABP insertion in those patients undergoing CABG alone remains uncertain. This review will give further insight into routine IABP use by presenting the basic principles and discussing current evidence.

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.

Perioperative intra-aortic balloon counterpulsation in a patient with myocardium at risk undergoing urgent noncardiac surgery

We are presenting the case of a 76-year-old female scheduled for major abdominal surgery. Her past medical history was remarkable for a three-vessel coronary artery disease, with a severely impaired left ventricular function. She had already undergone complex coronary artery bypass surgery. Currently, she presented with the rare constellation of a hemodynamic relevant and interventionally intractable stenosis of the left subclavian artery proximal to a crucial coronary bypass from left internal mammary artery to the left anterior descending. To protect this patient from perioperative myocardial infarction, an intra-aortic balloon pump was successfully used.

Prophylactic application of an intra-aortic balloon pump in high-risk patients undergoing off-pump coronary artery bypass grafting

BACKGROUND

An intra-aortic balloon pump (IABP) is the most commonly used circulatory assist device in cardiac surgery. We hypothesized that prophylactic application of an IABP improves early clinical outcome of high-risk patients undergoing scheduled off-pump coronary artery bypass grafting (OPCABG).

METHODS

From January 2010 to December 2013, hemodynamically stable, high-risk patients undergoing scheduled OPCABG with preincision use of an IABP were recruited to the IABP group. Using the propensity score-matching method, every patient in the IABP group was matched with another patient (the control group) with a similar propensity score who received an IABP on an as-needed basis during or after OPCABG. Surgical mortality and major morbidity rates were compared between groups.

RESULTS

A total of 116 patient pairs were included in this study. In patients in the IABP group, postoperative low cardiac output and respiratory as well as renal failure were less frequent, intensive care unit stay was shorter, and surgical mortality was lower compared to patients in the control group. In multivariate logistic regression, timing of IABP implantation, as an independent risk factor, was associated with postoperative low cardiac output (OR=2.02, 95% CI 1.28-5.76), respiratory failure (OR=1.86, 95% CI 1.19-4.27), renal failure (OR=2.96, 95% CI 1.51-6.63) and surgical mortality (OR=2.45, 95% CI 1.42-6.07).

CONCLUSIONS

Prophylactic application of an IABP improves postoperative cardiac performance, reduces respiratory and renal complications, and consequently lowers surgical mortality in high-risk patients undergoing scheduled OPCABG.

Long-term outcomes of coronary artery bypass grafting patients supported preoperatively with an intra-aortic balloon pump

OBJECTIVE

Most studies describing the outcome of coronary artery bypass grafting patients supported preoperatively with an intra-aortic balloon pump (IABP) have reported early results. The purpose of our study was to evaluate the early and long-term results.

METHODS

Of 2658 isolated coronary artery bypass grafting procedures performed from 1996 to 2001, 215 were supported preoperatively with an IABP. The indications for IABP insertion were cardiogenic shock in 18 (8.4%), acute evolving myocardial infarction in 38 (17.7%), clinical instability in 84 (39.1%), and critical coronary lesions in 75 (34.9%).

RESULTS

Operative mortality was 12.6%. The mortality of the cardiogenic shock patients was greater (22.2%; P=.174). Logistic regression analysis showed patient age (odds ratio, 1.057; 95% confidence interval, 1.010-1.108) and cardiopulmonary bypass (CPB) time (odds ratio, 1.020; 95% confidence interval, 1.008-1.031) were associated with increased operative mortality. An increased number of bypass grafts had a protective effect (odds ratio, 0.241; 95% confidence interval, 0.113-0.515). The actual early mortality was lower than the logistic EuroSCORE calculated mortality (12.6% vs 32.8%, P<.0001). The mean follow-up was 8±4 years. The Kaplan-Meier 10-year survival was 49%. The Cox adjusted overall (early and late) survival and major adverse cardiac events-free survival of the different IABP subgroups was similar. Cox analyses showed peripheral vascular disease, off-pump coronary artery bypass surgery, age, CPB time, female gender, and fewer bypass grafts were associated with decreased survival.

CONCLUSIONS

In patients supported preoperatively with an IABP, better early and long-term results were strongly related to younger age, a shorter CPB time, and a greater number of bypass grafts. Avoiding the use of CPB (off pump) in these emergency cases is not recommended.

"Polarizing" microplegia improves cardiac cycle efficiency after CABG for unstable angina

BACKGROUND

Myocardial protection during coronary artery bypass grafting (CABG) for unstable angina (UA) still represents a major challenge, ought to the risk for further ischemia/reperfusion injury. Few studies investigate the biochemical, hemodynamic and echocardiographic results of microplegia (Mic) in UA.

METHODS

Eighty UA-patients undergoing CABG were randomized to Mic (Mic-Group) or standard 4:1 blood Buckberg-cardioplegia (Buck-Group). Troponin-I and lactate were sampled from coronary sinus at reperfusion (T1), and from peripheral blood preoperatively (T0), at 6 (T2), 12 (T3) and 48 (T4) hours. Cardiac index (CI), indexed systemic vascular resistances (ISVR), Δp/Δt, cardiac cycle efficiency (CCE), and central venous pressure (CVP) were collected preoperatively (T0), and since Intensive Care Unit (ICU)-arrival (T1) to 24h (T5). Echocardiographic E-wave (E), A-wave (A), E/A, peak early-diastolic TDI-mitral annular-velocity (Ea), and E/Ea investigated the diastolic function and Wall Motion Score Index (WMSI) the systolic function, preoperatively (T0) and at 96h (T1).

RESULTS

Mic-Group showed lower troponin-I and lactate from coronary sinus (p=.0001 for both) and during the postoperative course (between-groups p=.001 and .0001, respectively). WMSI improved only after Mic (time-p=.001). Higher CI Δp/Δt and CCE (between-groups p=.0001), with comparable CVP and ISVR (p=N.S.) were detected after Mic. Diastolic function improved in both groups, but better after Mic (between-groups p=.003, .001, and .013 for E, E/A, and Ea, respectively). Mic resulted in lower transfusions (p=.006) and hospitalization (p=.002), and a trend towards lower need/duration of inotropes (p=.04 and p=.041, respectively), and ICU-stay (p=.015).

CONCLUSION

Microplegia attenuates myocardial damage in UA, reduces transfusions, improves postoperative systo-diastolic function, and shortens hospitalization.

Update on management strategies for separation from cardiopulmonary bypass

PURPOSE OF REVIEW

To update the reader about clinical management strategies for separation from cardiopulmonary bypass. A number of new drugs are being introduced in clinical practice, with significant utility in operative patient management. Further, there is increased routine use of complex devices to achieve separation from or avoidance of cardiopulmonary bypass.

RECENT FINDINGS

Selected medical and device strategies from the most recent literature will be discussed. First, the rationale for selected innovative agents to achieve myocardial performance is reviewed in four perioperative settings: agents for the management of myocardial dysfunction, vasomotor dysfunction, pulmonary hypertension, and right ventricular failure. Second is an evaluation of less commonly considered aspects of mechanical device use in the context of failure to wean from cardiopulmonary bypass or use to avoid cardiopulmonary bypass. Three devices will be discussed: intra-aortic balloon pump, ventricular assist devices, and extracorporeal membrane oxygenation.

SUMMARY

As our pharmacological and technological armamentarium improve, our population ages and procedures are attempted on patients with increasing co-morbid conditions, it will be important to both utilize newer pharmacological agents and consider innovative uses for device implementation to achieve optimal perioperative outcomes.

Preoperative intra aortic balloon pumps in patients undergoing coronary artery bypass grafting

BACKGROUND

The intra aortic balloon pump (IABP) is a mechanical assist device which improves cardiac function. The device has a well-established place in algorithms for managing low cardiac output following cardiac surgery. There is increasing evidence that certain cardiac surgery patients benefit from a period of preoperative augmentation with the intra aortic balloon pump.

OBJECTIVES

To determine the effect of the preoperative intra aortic balloon pump on mortality and morbidity in a number of different patients groups undergoing coronary artery bypass grafting.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 3, 2009), MEDLINE (2000 to August 2009), EMBASE (1998 to August 2009), BIOSIS previews (1969 to August 2009) and ISI Proceedings (1990 to August 2009) were searched. References and ongoing registers of studies were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of any size or length were included.

DATA COLLECTION AND ANALYSIS

Papers were assessed for inclusion by two authors independently and differences were settled by consensus with a third author. Date are presented in the form of odds ratios (OR) and 95% confidence intervals (CI).

MAIN RESULTS

Six trials were included (five on-pump and one off-pump). This update adds the results of one further trial. Data from a total of 255 patients were included in the meta-analysis of mortality outcomes; all on-pump. Generally, the patients were considered as "high risk" and 132 were treated preoperatively with IABP and 123 served as controls. There were four hospital deaths in the intervention arm and 23 in the non-intervention arm (OR 0.18, 95% CI 0.08 to 0.41; P<0.0001). In a subgroup analysis, low cardiac index (<2.0 L/min/m(2)) was noted in 21 out of 105 patients in the treatment arm and 59 patients out of 88 in the non-treatment arm (OR 0.14, 95% CI: 0.08 to 0.25; P<0.00001). An off-pump versus on-pump analysis was not possible due to the limited number of off-pump studies. However a single well-conducted RCT suggested favourable effect of the preoperative IABP in off-pump patients.

AUTHORS' CONCLUSIONS

Evidence suggests that preoperative IABP may have a beneficial effect on mortality and morbidity in specific high risk patient groups undergoing coronary artery bypass grafting, however there are many problems with the quality, validity and generalisability of the trials. However, the available evidence is not robust enough to extend the use of IABP to truly elective, high risk patients. Defining more precisely which patient groups may benefit would be the challenge for the future.

ECG-triggered skeletal muscle stimulation improves hemodynamics and physical performance of heart failure patients

BACKGROUND

Muscular counterpulsation (MCP) was developed for circulatory assistance by stimulation of peripheral skeletal muscles. We report on a clinical MCP study in patients with and without chronic heart failure (CHF).

METHODS AND RESULTS

MCP treatment was applied (30 patients treated, 25 controls, all under optimal therapy) for 30 minutes during eight days by an ECG-triggered, battery-powered, portable pulse generator with skin electrodes inducing light contractions of calf and thigh muscles, sequentially stimulated at early diastole. Hemodynamic parameters (ECG, blood pressure and echocardiography) were measured one day before and one day after the treatment period in two groups: Group 1 (9 MCP, 11 no MCP) with ejection fraction (EF) above 40% and Group 2 (21 MCP, 14 no MCP) below 40%. In Group 2 (all patients suffering from CHF) mean EF increased by 21% (p<0.001) and stroke volume by 13% (p<0.001), while end systolic volume decreased by 23% (p<0.001). In Group 1, the increase in EF (6%) and stroke volume (8%) was also significant (p<0.05) but less pronounced than in Group 2. Physical exercise duration and walking distance increased in Group 2 by 56% and 72%, respectively.

CONCLUSIONS

Noninvasive MCP treatment for eight days substantially improves cardiac function and physical performance in patients with CHF.