Asian Cardiovasc Thorac Ann 2002;10:302-305
© 2002 Asia Publishing EXchange Pte Ltd
Preoperative Intraaortic Balloon Pump for Salvage Myocardial Revascularization
Jan T Christenson, MD
|
Clinic for Cardiovascular Surgery University Hospital Geneva, Switzerland
|
|
|
For reprint information contact: Jan T Christenson, MD Tel: 41 22 372 7630 Fax: 41 22 372 7634 email: JTChristenson{at}hotmail.com Clinic for Cardiovascular Surgery, University Hospital, rue Micheli-du-Crest 24, CH-1211 Geneva 14, Switzerland.
|
 |
ABSTRACT
|
|---|
The benefit of preoperative intraaortic balloon pumping on hospital and 1-year mortality was assessed in 17 consecutive patients with cardiogenic shock who underwent salvage coronary artery bypass surgery between January 1996 and May 2000. Mean preoperative cardiac index was 1.57 ± 0 23 L.min-1.m-2. Hemodynamic stability was achieved prior to surgery in 14 patients, and mean cardiac index increased to 2.28 ± 0.64 L.min-1.m-2. Hospital mortality was 5.9% (1 patient). Five patients required postoperative intraaortic balloon pumping because of low cardiac output. The duration of intensive care, hospital stay, and the total procedural cost were similar to those reported for high-risk coronary bypass grafting. Cardiac event-free survival was 88.2% (15/17) at 1 year. Intraaortic balloon pumping promises to be an effective therapy for patients in cardiogenic shock who subsequently undergo surgical myocardial revascularization as a salvage procedure.
|
INTRODUCTION
|
|---|
Intraaortic balloon pumping (IABP) is an established adjunct to pharmacological treatment of the failing heart after myocardial infarction (MI), unstable angina, or cardiac surgery.1 Afterload is reduced and diastolic pressure is augmented, resulting in increased stroke volume and cardiac output, thus creating a more favorable balance of myocardial supply and demand.2 The use of IABP has shown survival advantages for patients with acute MI complicated by cardiogenic shock, as a bridge to myocardial revascularization.3 Coronary artery bypass grafting (CABG) in high-risk coronary patients is associated with a high hospital mortality and postoperative morbidity, most often due to poor postoperative cardiac performance.4,5 The introduction of preoperative IABP for high-risk coronary patients undergoing CABG has improved the outcome.6,7 For patients with endstage coronary artery disease or cardiogenic shock, hospital mortality is very high.8,9 Preoperative IABP to improve myocardial perfusion prior to surgery would allow revascularization in a less ischemic heart and should reduce the risk of severely compromised myocardial function postoperatively.4,10 The impact of preoperative IABP on hospital and 1-year mortality in patients with cardiogenic shock who subsequently underwent myocardial revascularization as a salvage procedure was evaluated.
|
PATIENTS AND METHODS
|
|---|
From January 1996 to May 2000, 17 consecutive patients presenting with cardiogenic shock received IABP in addition to standard medical therapy, and subsequently underwent CABG as a salvage procedure. Preoperative patient characteristics are listed in Table 1
. Cardiogenic shock was defined as systolic blood pressure below 90 mm Hg for 30 minutes, unresponsive to fluid therapy alone, attributed to cardiac dysfunction, and associated with either signs of hypoperfusion or a cardiac index < 2 L.min-1.m-2 with capillary wedge pressure > 18 mm Hg, systemic vascular resistance > 1,800 dyne.sec.cm-5, and a stroke work index < 25 g.m-2. Low cardiac output was defined as a cardiac index < 2 L.min-1.m-2. The Euroscore for CABG patients was used for risk stratification. Standard anesthesic, surgical, and cardiopulmonary bypass techniques were employed. All operations were performed under normothermic cardiopulmonary bypass (35ºC to 37ºC). Myocardial protection was achieved by intermittent antegrade cold cardioplegia (8ºC to 10ºC) with St. Thomas’ Hospital no. 2 solution, and local cardiac cooling with ice slush. The internal thoracic artery was used whenever possible for revascularization of the anterolateral part of the heart. A sequential vein bypass graft was used for revascularization of the posterolateral region. No other arterial grafts were used during the study period. All patients had a Swan-Ganz catheter placed prior to surgery.
For IABP, an 8F or 9.5F Percor STAT-DL balloon catheter (Datascope Corp., Fairfield, NJ, USA) with a 30 or 40-mL balloon was connected to a Datascope pump console. Routinely, the balloon catheter was placed by percutaneous insertion via a femoral artery; surgical placement was undertaken only if percutaneous placement failed. All patients treated with IABP (preoperatively or postoperatively) received prophylactic antibiotics and intravenous heparin with a target prothrombin time above 40 seconds. For preoperative IABP, balloon catheter insertion was carried out in the cardiac catheterization laboratory prior to diagnostic coronary angiography in all patients. Those found suitable for percutaneous cardiological interventions were excluded from this study. The duration of preoperative IABP varied from 1 to 6 hours prior to aortic crossclamping. There was no failure to place the intraaortic balloon catheter. The indication for resumption of IABP postoperatively was when the cardiac index could not be maintained above 2 L.min-1.m-2 despite massive inotropic support (dopamine at 15 µg.kg-1.min-1, dobutamine at 5 to 10 µg.kg-1.min-1, amrinone in a bolus dose of 0.5 mg.kg-1, or a combinations thereof) together with appropriate volume loading. The IABP was terminated once hemodynamic stability had been restored, maintaining a cardiac index of 2 L.min-1.m-2, with only dopamine at 5µg.kg-1.min-1 for inotropic support.
Economic data regarding procedural costs for each patient were obtained from the hospital finance department’s database and expressed as the total procedural cost. All patients discharged from the hospital alive were followed clinically during the first postoperative year. Death, recurrence of ischemic symptoms, MI, or need for secondary interventions (percutaneous transluminal coronary angioplasty or redo CABG) were registered. Where possible, data are presented as mean ± standard deviation.
|
RESULTS
|
|---|
Hemodynamic stability was achieved prior to surgery in 14 patients (82%). The preoperative IABP time was 3.5 ± 1.2 hours. All patients had percutaneous balloon catheter insertion. Ten patients (59%) had resumption of IABP postoperatively because cardiac index could not be maintained despite massive inotropic support and adequate volume loading. The mean postoperative duration of IABP was 18.9 ± 2.9 hours (range, 5 to 48 hours). There were no IABP-related deaths, and only 1 patient had an IABP-related complication: minor limb ischemia that resolved on removal of the balloon catheter. The mean number of distal anastomoses was 3.7 ± 1.2 (range, 1 to 6), and coronary thromboendarterectomy was required in 5 patients (29%). The internal thoracic artery was used as conduit in 11 patients (65%). Aortic crossclamp time was 64.2 ± 20.5 minutes, and cardiopulmonary bypass time was 79.4 ± 17 minutes.
Other postoperative results are shown in Table 2. There was only 1 hospital death (< 30 days after surgery) in a 68-year-old woman who presented with multiple risk factors: cardiogenic shock, emergency operation, left ventricular ejection fraction of 0.18, 90% left main stenosis, previous CABG, and a Euroscore of 13. The cause of death was left ventricular failure. For all 17 patients, the mean preoperative cardiac index was 1.57 ± 0.23 L.min-1.m-2 and it increased significantly to 2.28 ± 0.64 L.min-1.m-2 at the start of IABP. In the first 72 hours after surgery, cardiac index remained significantly higher than the preoperative level (Figure 1). However, 5 patients experienced low cardiac output postoperatively. Intensive care unit stay was 44 ± 26.1 hours (range, 11 to 141 hours), hospital stay was 13.1 ± 5 days (range, 5 to 56 days), and the procedural cost was 39,243 ± 9,479 Swiss Francs. During follow-up, none of the patients had recurrent angina but there was one sudden death as a result of acute MI. Cardiac event-free survival at 1 year was 88.2% (15/17).
View larger version (64K):
[in this window]
[in a new window]
|
Figure 1. Mean cardiac index before and after revascularization in patients receiving preoperative intraaortic balloon pumping. B1 = before balloon pumping, B2 = before aortic crossclamping; postoperative times start on weaning from cardiopulmonary bypass.
|
|
|
DISCUSSION
|
|---|
The characteristics of coronary patients are steadily changing and more are referred for surgical revascularization with unstable angina, evolving MI, and cardiogenic shock. Many have diffuse coronary artery disease, often classified as endstage coronary disease.11 In many institutions, this type of coronary patient is denied surgery, being regarded as too high an operative risk. Intraaortic balloon counterpulsation has provided essential circulatory support for numerous patients experiencing hemodynamic instability due to severe myocardial ischemia, including those in cardiogenic shock, and it has been reported to be effective in reducing mortality.12–14 The use of preoperative IABP in high-risk coronary patients undergoing either CABG or angioplasty has been advocated recently.5,7,15 Several studies have indicated both efficacy and cost-effectiveness of such therapy.5,13,15 A possible reason for the positive impact of preoperative IABP is that the process of left ventricular dilation and remodeling begins within the first 24 hours after MI.16 Patients with evolving MI complicated by cardiogenic shock have also benefited from preoperative IABP in combination with thrombolytic therapy.14 There have been several reports of the effects of IABP on hemodynamics in patients in cardiogenic shock or with evolving MI, mainly in the cardiology literature. Cardiac index was noted to increase by 0.5 to 0.8 L.min-1.m-2, mean arterial pressure improved together with a marked decrease in pulmonary wedge pressure, and the shock syndrome was reversed in 88% to 100% of patients.3
The patients in this series undergoing salvage CABG with preoperative IABP had a low hospital mortality and acceptable postoperative morbidity, compatible with earlier findings in less severely ill coronary patients undergoing CABG.3,5,7,10 The time required in the intensive care unit and the total hospital stay were no longer than those noted previously in moderate to low-risk CABG patients.15 This study also demonstrated that when these severely ill patients survive the immediate postoperative period, their potential longer-term outcome is encouraging.8 The IABP-related major complication rate in this series was low (5.9%) which concurs with a recent report.6 Smaller sized balloon catheters, better education, more IABP experience, and careful surveillance are the keys to keeping balloon-related complication rates at a low level. These findings strongly support the use of preoperative IABP in patients undergoing CABG as a salvage procedure. Thus, preoperative IABP is likely extend the indications for surgical myocardial revascularization to include patients presenting in cardiogenic shock, a cohort rarely operated upon today.
|
REFERENCES
|
|---|
- Bolooki H. Clinical application of intraaortic balloon pump. 3rd ed. New York: Futura, 1998.
- Gill CC, Wechsler A, Newman G, Oldham H. Augmentation and redistribution of myocardial blood flow during acute ischemia by intraaortic balloon pumping. Ann Thorac Surg
1973;16:445–53.[Medline]
- Waksman R, Weiss AT, Gotsman MS, Hassin Y. Intraaortic balloon counterpulsation improves survival in cardiogenic shock complicating acute myocardial infarction. Eur Heart J
1993;14:71–4.[Abstract/Free Full Text]
- Cristakis GT, Weisel RD, Fremes SE, Ivanov J, David TE, Goldman BS, et al. Coronary artery bypass grafting in patients with poor ventricular function. J Thorac Cardiovasc Surg
1992;103:1083–92.[Abstract]
- Christenson JT, Simonet F, Badel P, Schmuziger M. Evaluation of preoperative intraaortic balloon pump support in high-risk coronary patients. Eur J Cardio-thorac Surg
1997;11:1097–103.[Abstract]
- Christenson JT, Simonet F, Badel P, Schmuziger M. Optimal timing of preoperative intraaortic balloon pump support in high-risk coronary patients. Ann Thorac Surg
1999;68:934–9.[Abstract/Free Full Text]
- Holman WL, Li Q, Kiefe CI, McGiffin DC, Peterson ED, Allman RM, et al. Prophylactic value of pre-incision intraaortic balloon pump: analysis of a statewide experience. J Thorac Cardiovasc Surg
2000;120:1112–9.[Abstract/Free Full Text]
- Christenson JT, Maurice J, Simonet F, Bloch A, Fournet PC, Velebit V, et al. Effect of low left ventricular ejection fractions on outcome of primary coronary bypass grafting in endstage coronary artery disease. J Cardiovasc Surg
(Torino) 1995;36:45–51.[Medline]
- Milano C, White W, Smith R, Jones R, Lowe C, Smith P, et al. Coronary artery bypass in patients with severely depressed ventricular function. Ann Thorac Surg
1993;56:487–93.[Abstract]
- Bates ER, Stomel RJ, Hochman JS, Ohman EM. The use of intraaortic balloon counterpulsation as an adjunct to reperfusion therapy in cardiogenic shock. Int J Cardiol
1998;6(Suppl 1):S37–42.
- Plume SK, O’Connor GT, Olmstead EM. As originally published in 1994: Changes in patients undergoing coronary artery bypass grafting: 1987-1990. Updated in 2000. Northern New England Cardiovascular Disease Study Group. Ann Thorac Surg
2001;72:314–5.[Abstract/Free Full Text]
- Ohman EM, George BS, White CJ, Kern MJ, Gurbel PA, Freedman RJ, et al. Use of aortic counterpulsation to sustain coronary artery patency during acute myocardial infarction: results of randomized trial. Circulation
1994;90:772–9.
- Stone GW, Marsalese D, Brodie BR, Griffin JJ, Donohue B, Constantini C, et al. A prospective randomized evaluation of prophylactic intraaortic balloon counterpulsation in high risk patients with acute myocardial infarction treated with primary angioplasty. J Am Coll Cardiol
1997;29:1459–67.[Abstract]
- Barron HV, Every NR, Parsons LS, Angeja B, Goldberg RJ, Gore JM, et al. The use of intraaortic balloon counterpulsation in patients with cardiogenic shock complicating acute myocardial infarction: data from the National Registry of Myocardial Infarction 2. Am Heart J
2001;141:933–9.[Medline]
- Christenson JT, Simonet F, Schmuziger M. Economic impact of preoperative intraaortic balloon pump therapy in high-risk coronary patients. Ann Thorac Surg
2000;70:510–5.[Abstract/Free Full Text]
- Firth BG, Dunnmon PM. The prevention of congestive heart failure: left ventricular dilation and its management. Am J Med Sci
1990;299:276–90.[Medline]
TOP
ABSTRACT
INTRODUCTION
