Intra-aortic Balloon Pump In Patients Research Articles

Descending aortic calcification increases renal dysfunction and in-hospital mortality in cardiac surgery patients with intraaortic balloon pump counterpulsation placed perioperatively: a case control study

IntroductionAcute kidney injury (AKI) after cardiac surgery increases length of hospital stay and in-hospital mortality. A significant number of patients undergoing cardiac surgical procedures require perioperative intra-aortic balloon pump (IABP) support. Use of an IABP has been linked to an increased incidence of perioperative renal dysfunction and death. This might be due to dislodgement of atherosclerotic material in the descending thoracic aorta (DTA). Therefore, we retrospectively studied the correlation between DTA atheroma, AKI and in-hospital mortality.MethodsA total of 454 patients were retrospectively matched to one of four groups: -IABP/-DTA atheroma, +IABP/-DTA atheroma, -IABP/+DTA atheroma, +IABP/+DTA atheroma. Patients were then matched according to presence/absence of DTA atheroma, presence/absence of IABP, performed surgical procedure, age, gender and left ventricular ejection fraction (LVEF). DTA atheroma was assessed through standard transesophageal echocardiography (TEE) imaging studies of the descending thoracic aorta.ResultsBasic patient characteristics, except for age and gender, did not differ between groups. Perioperative AKI in patients with -DTA atheroma/+IABP was 5.1% versus 1.7% in patients with -DTA atheroma/-IABP. In patients with +DTA atheroma/+IABP the incidence of AKI was 12.6% versus 5.1% in patients with +DTA atheroma/-IABP. In-hospital mortality in patients with +DTA atheroma/-IABP was 3.4% versus 8.4% with +DTA atheroma/+IABP. In patients with +DTA atheroma/+IABP in hospital mortality was 20.2% versus 6.4% with +DTA atheroma/-IABP. Multivariate logistic regression identified DTA atheroma > 1 mm (P = *0.002, odds ratio (OR) = 4.13, confidence interval (CI) = 1.66 to 10.30), as well as IABP support (P = *0.015, OR = 3.04, CI = 1.24 to 7.45) as independent predictors of perioperative AKI and increased in-hospital mortality. DTA atheroma in conjunction with IABP significantly increased the risk of developing acute kidney injury (P = 0.0016) and in-hospital mortality (P = 0.0001) when compared to control subjects without IABP and without DTA atheroma.ConclusionsPerioperative IABP and DTA atheroma are independent predictors of perioperative AKI and in-hospital mortality. Whether adding an IABP in patients with severe DTA calcification increases their risk of developing AKI and mortality postoperatively cannot be clearly answered in this study. Nevertheless, when IABP and DTA are combined, patients are more likely to develop AKI and to die postoperatively in comparison to patients without IABP and DTA atheroma.

Levosimendan Versus Intra-aortic Balloon Pump in High-Risk Cardiac Surgery Patients

Patients with severe left ventricular dysfunction receive inotropic and mechanical circulatory support with an intra-aortic balloon pump (IABP) during the perioperative phase of cardiac surgery. The authors performed the first comparison of levosimendan versus an IABP in patients with poor left ventricular function undergoing cardiac surgery. A case-matched study. A teaching hospital. Twenty-two heart failure patients scheduled to undergo elective coronary artery bypass graft surgery with or without concomitant mitral surgery. Eleven patients received levosimendan at a dose of 0.1 μg/kg/min for 24 hours without an initial bolus. The control group, also 11 patients, received a preoperative IABP. The intensive care unit stay was the major endpoint of this study. Biochemical, hemodynamic, and echocardiographic data were collected together with the time on mechanical ventilation and 30-day mortality. The length of intensive care unit stay was reduced in patients receiving levosimendan (median, 2.5; range, 1-3 days) compared with those receiving an IABP (median, 5; range, 3-6 days; p = 0.01). No deaths occurred in the levosimendan group; 1 patient died in the intra-aortic balloon pump group. Patients receiving levosimendan had a shorter duration of intensive care stay than peers who received a preoperative IABP. The findings of this pilot study should be investigated further in a large randomized controlled study.

A Clinical Score to Predict the Need for Intraaortic Balloon Pump in Patients Undergoing Coronary Artery Bypass Grafting

A Clinical Score to Predict the Need for Intraaortic Balloon Pump in Patients Undergoing Coronary Artery Bypass Grafting

E0459 Primary evaluation to safety and value of IABP in patients with acute coronary syndrome complicated with pump failure

ObjectiveTo evaluate the therapeutic effect and safety, and the result of coronary angiography (CAG) and serum brain natriuretic peptide (BNP) level in patients with acute coronary syndrome complicated with pump...

A Clinical Score to Predict the Need for Intraaortic Balloon Pump in Patients Undergoing Coronary Artery Bypass Grafting

There is no accepted consensus on the definition of high-risk patients who may benefit from the use of intraaortic balloon pump (IABP) in coronary artery bypass grafting (CABG). The aim of this study was to develop a risk model to identify high-risk patients and predict the need for IABP insertion during CABG. From April 1996 to December 2006, 8,872 consecutive patients underwent isolated CABG; of these 182 patients (2.1%) received intraoperative or postoperative IABP. The scoring risk model was developed in 4,575 patients (derivation dataset) and validated on the remaining patients (validation dataset). Predictive accuracy was evaluated by the area under the receiver operating characteristic curve. Mortality was 1% in the entire cohort and 18.7% (22 patients) in the group which received IABP. Multivariable analysis showed that age greater than 70 years, moderate and poor left ventricular dysfunction, previous cardiac surgery, emergency operation, left main disease, Canadian Cardiovascular Society 3-4 class, and recent myocardial infarction were independent risk factors for the need of IABP insertion. Three risk groups were identified. The observed probability of receiving IABP and mortality in the validation dataset was 36.4% and 10% in the high-risk group (score >14), 10.9% and 2.8% in the medium-risk group (score 7 to 13), and 1.7% and 0.7% in the low-risk group (score 0 to 6). This simple clinical risk model based on preoperative clinical data can be used to identify high-risk patients who may benefit from elective insertion of IABP during CABG.

An option for intraoperative placement of an intra-aortic balloon pump in patients with occlusive peripheral vascular disease

An option for intraoperative placement of an intra-aortic balloon pump in patients with occlusive peripheral vascular disease

Intraaortic Balloon Pumping in Patients with Right Ventricular Insufficiency after Cardiac Surgery: Parameters to Predict Failure of IABP Support

The indications for intra-aortic balloon pump (IABP) in the case of a failing right ventricle after operations with extracorporeal circulation (ECC) are still discussed controversially. We investigated the benefit of IABP in patients with a predominantly right ventricular dysfunction after ECC. Additionally, we wanted to identify early and easily available prognostic markers for outcome in all patients receiving IABP support. Between 1/2004 and 1/2008, 4550 patients underwent cardiac surgical procedures with ECC, 223 of whom (4.9 %) had an IABP inserted intra- or postoperatively (group 1). 79 of these patients were treated intraoperatively with IABP for early postoperative low cardiac output syndrome (LCOS) characterized by predominantly right ventricular failure (RV group). Clinical data and hemodynamic variables were recorded perioperatively. Multiple potential markers of mortality and postoperative complications were analyzed statistically, especially with regard to their predictive ability. 68 % of all IABP patients were successfully weaned from IABP support and 63 % survived to hospital discharge. In the RV group, cardiac index (CI) and mean arterial pressure (MAP) increased (CI 1.8 +/- 0.2 to 2.8 +/- 0.2, MAP 53 +/- 10 to 73 +/- 8, P < 0.05) within 1 hour after IABP, whereas central venous pressure (CVP) and pulmonary artery wedge pressure (PAWP) decreased ( P < 0.05). 59 patients in the RV group (75 %) could be weaned from IABP successfully and 69 % survived to hospital discharge. Serum lactate of more than 11 mmol/L in the first 10 hours of IABP support predicted a 100 % mortality. A base deficit of more than 12 mmol/L, mean arterial pressure less than 55 mmHg, urine output of less than 50 ml/h for 2 hours, and dose of epinephrine or norepinephrine of more than 0.4 mg/kg/min were other highly predictive prognostic markers. Furthermore, multivariate analysis showed that patients with a left atrial pressure > 17 mmHg or a mixed venous saturation (SVO (2)) < 65 % had poor outcomes. In patients with IABP support for postcardiotomy cardiogenic shock, elevated serum lactate, elevated base deficit, hypotension, oliguria and large vasopressor doses are all predictors of mortality. In these patients, the use of another mechanical assist device should be considered in good time. Our study additionally shows that LCOS caused by predominantly right ventricular failure - particularly after CABG - may be an additional indication for IABP.

Evaluating percutaneous support for cardiogenic shock: data shock and sticker shock

Cardiogenic shock, a state of systemic hypoperfusion resulting from cardiovascular dysfunction, is the leading cause of death in patients with ST-elevation myocardial infarction (STEMI).1 In spite of tremendous advances in cardiovascular care over the past two decades, mortality rates for patients with cardiogenic shock remain quite high, with some estimates as high as 50%.2 Given the underlying pathophysiology of cardiogenic shock, most commonly attributed to left ventricular failure resulting from STEMI, prompt institution of mechanical circulatory support seems intuitively important. The intra-aortic balloon pump (IABP) counterpulsation device was first introduced in the 1960s and has gained widespread acceptance as the device of choice for most patients with cardiogenic shock. Registry data suggest that cardiogenic shock is one of the most common conditions for which IABPs are used, accounting for 20% of all insertions.3 In fact, the ESC and ACC/AHA guidelines on STEMI strongly endorse the placement of an IABP in patients with cardiogenic shock refractory to pharmacological therapy.4,5 However, the evidence base from which these recommendations emanate is limited. There are no large randomized controlled trials which have rigorously evaluated the impact of IABPs in cardiogenic shock. Observational data from the Should We Emergently Revascularize Occluded Coronary Arteries in Shock (SHOCK) trial registry as well as the National Registry of Myocardial Infarction (NRMI)-2 suggest that patients treated with an IABP in addition to thrombolytics had lower in-hospital mortality than those receiving thrombolytics alone.6,7 Notably, patients undergoing primary percutaneous coronary intervention (PCI) in NRMI-2 did not benefit from IABP placement. A recent systematic review of >10 000 patients with cardiogenic shock in the setting of acute myocardial infarction (AMI) published in the European Heart Journal presented similar findings and concluded by challenging contemporary clinical guidelines.8 One of the theoretical shortcomings of … *Corresponding author. Tel: +1 857 203 6840/6841, Fax: +1 857 203 5550, Email: dlbhattmd{at}alum.mit.edu

Preoperative Intra-Aortic Balloon Pump in Patients Undergoing Coronary Bypass Surgery: A Systematic Review and Meta-Analysis

To assess the effectiveness of preoperative intra-aortic balloon pump (IABP) placement in high-risk patients undergoing coronary bypass surgery (CABG). The primary outcome was hospital mortality and secondary outcomes were IABP-related complications (bleeding, leg ischemia, aortic dissection). MEDLINE, EMBASE, Cochrane registry of Controlled Trials, and reference lists of relevant articles were searched. We included randomized controlled trials (RCTs), and cohort studies that fulfilled our a priori inclusion criteria. Eligibility decisions, relevance, study validity, and data extraction were performed in duplicate using pre-specified criteria. Meta-analysis was conducted using a random effects model. Ten publications fulfilled our eligibility criteria, of which four were RCTs and six were cohort studies with controls. There were statistical as well as clinical heterogeneity among included studies. A total of 1034 patients received preoperative IABP and 1329 did not receive preoperative IABP. The pooled odds ratio (OR) for hospital mortality in patients treated with preoperative IABP was 0.41 (95% CI, 0.21-0.82, p = 0.01). The number needed to treat was 17. The pooled OR for hospital mortality from randomized trials was 0.18 (95% CI, 0.06-0.57, p = 0.003) and from cohort studies was 0.54 (95% CI, 0.24-1.2, p = 0.13). Overall, 3.7% (13 of 349) of patients who received preoperative IABP developed either limb ischemia or haematoma at the IABP insertion site, and most of these complications improved after discontinuation of IABP. Evidence from this meta-analysis support the use of preoperative IABP in high-risk patients to reduce hospital mortality.

755 The benefits of intraaortic balloon pumping in patients with end-stage chronic heart failure due to associated right ventricular dysfunction

755 The benefits of intraaortic balloon pumping in patients with end-stage chronic heart failure due to associated right ventricular dysfunction

Effect of early and late use of intraaortic balloon pumping in patients undergoing cardiac surgery on parameters of tissue oxygenation

Effect of early and late use of intraaortic balloon pumping in patients undergoing cardiac surgery on parameters of tissue oxygenation

Derivation and validation of a clinical scoring system to predict the need for an intra-aortic balloon pump in patients undergoing adult cardiac surgery

The spectrum of patients receiving cardiac surgery are increasing in age and severity of illness. With the reduction of complications caused by the placement of an intra-aortic balloon pump (IABP) there is increasing interest in the placement of an IABP prophylactically. We sought to derive a scoring system to guide the placement of IABPs. A total of 3927 patients from the Blackpool Victoria Open Heart Registry were used to derive a range of clinical decision scores using a range of established and novel statistical techniques. This database included 127 patients who received an IABP. The derived scores and rules were then validated on the North Staffordshire Open Heart Registry, containing 3070 patients, and 161 patients who received an IABP. We derived and validated a clinical score that has a sensitivity of 50% and a specificity of 96.5% in the prediction of those patients requiring an IABP. This was robust in the validation dataset and outperformed the Parsonnet score in this context. Our validated clinical scoring system will be useful both to guide individual clinical decision making and to compare variation of IABP usage among institutions.

Intra-aortic balloon pump in patients with ischaemic heart disease undergoing oesophagogastrectomy

Oesophagogastrectomy for carcinoma has a high operative mortality rate. Patients are elderly and ischaemic heart disease (IHD) is a recognised and frequent risk factor. To illustrate the use of the intra-aortic balloon pump (IABP) as prophylaxis against cardiac complications in a group of such patients. Five patients aged from 63 to 78 years were presented with operable adenocarcinoma of the oesophagus. They had IHD of a severity thought to pose a risk of myocardial infarction (MI) and/or failure at the time of oesophagogastrectomy. With the induction of anaesthesia, the IABP was inserted and left in situ for up to 24 hours. There were no major adverse perioperative cardiac events. Four patients were discharged from hospital on the eighth and one on the tenth postoperative day. The prophylactic use of IABP has a potential role in the prevention of cardiac complications in patients with IHD undergoing high risk non-cardiac surgery.

Usefulness of percutaneous left ventricular assistance to support high-risk percutaneous coronary interventions

Percutaneous coronary intervention (PCI) has been proposed as a measure to alleviate symptoms and improve prognosis in patients with atherosclerotic heart disease and depressed heart function. Nonetheless, the risk of ischemic complications during or after the procedure is potentially increased in these patients. A number of supportive techniques have been described for high-risk angioplasty 1 Shawl F.A. Quyyumi A.A. Bajaj S. Hoff S.B. Dougherty K.G. Percutaneous cardiopulmonary bypass-supported coronary angioplasty in patients with unstable angina pectoris or myocardial infarction and a left ventricular ejection fraction ≤25%. Am J Cardiol. 1996; 77: 14-19 Abstract Full Text PDF PubMed Scopus (25) Google Scholar , 2 Scholz K.H. Dubois-Rande J.L. Urban P. Morice M.C. Loisance D. Smalling R.W. Figulla H.R. Clinical experience with the percutaneous hemopump during high-risk coronary angioplasty. Am J Cardiol. 1998; 82: 1107-1110 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar , 3 Dubois-Rande J.L. Teiger E. Garot J. Aptecar E. Pernes J.M. Tixier D. Gueret P. Loisance D. Dupouy P. Effects of the 14F hemopump on coronary hemodynamics in patients undergoing high-risk coronary angioplasty. Am Heart J. 1998; 135: 844-849 Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar , 4 Schreiber T.L. Kodali U.R. O’Neill W.W. Gangadharan V. Puchrowicz-Ochocki S.B. Grines C.L. Comparison of acute results of prophylactic intraaortic balloon pumping with cardiopulmonary support for percutaneous transluminal coronary angioplasty (PCTA). Cathet Cardiovasc Diagn. 1998; 45: 115-119 Crossref PubMed Scopus (22) Google Scholar , 5 Kaul U. Sahay S. Bahl V.K. Sharma S. Wasir H.S. Venugopal P. Coronary angioplasty in high risk patients comparison of elective intraaortic balloon pump and percutaneous cardiopulmonary bypass support—a randomized study. J Interv Cardiol. 1995; 8: 199-205 Crossref PubMed Scopus (18) Google Scholar ; however, no single approach has achieved wide acceptance. Limited effectiveness in the actual support 6 Taguchi I. Ogawa K. Oida A. Abe S. Kaneko N. Sakio H. Comparison of hemodynamic effects of enhanced external counterpulsation and intra-aortic balloon pumping in patients with acute myocardial infarction. Am J Cardiol. 2000; 86: 1139-1141 Abstract Full Text Full Text PDF PubMed Scopus (69) Google Scholar and device-related complications 2 Scholz K.H. Dubois-Rande J.L. Urban P. Morice M.C. Loisance D. Smalling R.W. Figulla H.R. Clinical experience with the percutaneous hemopump during high-risk coronary angioplasty. Am J Cardiol. 1998; 82: 1107-1110 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar , 4 Schreiber T.L. Kodali U.R. O’Neill W.W. Gangadharan V. Puchrowicz-Ochocki S.B. Grines C.L. Comparison of acute results of prophylactic intraaortic balloon pumping with cardiopulmonary support for percutaneous transluminal coronary angioplasty (PCTA). Cathet Cardiovasc Diagn. 1998; 45: 115-119 Crossref PubMed Scopus (22) Google Scholar , 7 Alderman J.D. Gabliani G.I. McCabe C.H. Brewer C.C. Lorell B.H. Pasternak R.C. Skillman J.J. Steer M.L. Baim D.S. Incidence and management of limb ischemia with percutaneous wire-guided intraaortic balloon catheters. J Am Coll Cardiol. 1987; 9: 524-530 Abstract Full Text PDF PubMed Scopus (87) Google Scholar have hampered a more widespread use of these methods. Recently, a newly developed percutaneous left ventricular assist device (pVAD) has been demonstrated to effectively reverse cardiogenic shock after myocardial infarction (Tandem Heart pVAD; Cardiac Assist Technologies, Inc., Ithaca, New York). 8 Thiele H. Lauer B. Hambrecht R. Boudriot E. Cohen H.A. Schuler G. Reversal of cardiogenic shock by percutaneous left atrial-to-femoral arterial bypass assistance. Circulation. 2001; 104: 2917-2922 Crossref PubMed Scopus (233) Google Scholar This system is readily deployed by percutaneous approach in the catheterization laboratory and is able to provide a systemic output of up to 4 L/min. An inflow cannula is inserted into the left atrium via transseptal puncture and the oxygenated blood is diverted to the femoral artery by a low-speed centrifugal continuous-flow pump. In this study, we report on a series of patients who underwent high-risk PCI supported by the Tandem Heart pVAD.

Usefulness of external counterpulsation early postoperatively after the Fontan procedure in children

External counterpulsation (EC) is a noninvasive circulatory assistance technique that improves coronary blood flow and myocardial performance, augments systemic venous return, and reduces ventricular afterload. 1 Lawson W.E. Hui J.C.K. Zheng Z.S. Oster Z. Katz J.P. Diggs P. Burger L. Cohn C.D. Soroff H.S. Cohn P.F. Three-year sustained benefit from enhanced external counterpulsation in chronic angina pectoris. Am J Cardiol. 1995; 75: 840-841 Abstract Full Text PDF PubMed Scopus (86) Google Scholar , 2 Taguchi I. Ogawa K. Oida A. Abe S. Kaneko N. Sakio H. Comparison of hemodynamic effects of enhanced external counterpulsation and intra-aortic balloon pumping in patients with acute myocardial infarction. Am J Cardiol. 2000; 86: 1139-1141 Abstract Full Text Full Text PDF PubMed Scopus (69) Google Scholar , 3 Urano H. Ikeda H. Ueno T. Matsumoto T. Murohara T. Imaizumi T. Enhanced external counterpulsation improves exercise tolerance, reduces exercise-induced myocardial ischemia and improves left ventricular diastolic filling in patients with coronary artery disease. J Am Coll Cardiol. 2001; 37: 93-99 Abstract Full Text Full Text PDF PubMed Scopus (141) Google Scholar We hypothesized that EC could benefit patients who underwent the Fontan procedure by improving cardiac output in the early postoperative period. EC had not been studied in the postoperative setting, and had never previously performed in the pediatric population. Therefore, this investigation sought to provide preliminary evidence of EC safety and short-term efficacy in children after Fontan surgery.

Creatine kinase-MB fraction elevation after percutaneous coronary intervention in patients with chronic renal failure

We evaluated the short- and long-term clinical outcomes of 326 consecutive patients with chronic renal failure, not on dialysis, who had creatine kinase (CK)-myocardial band (MB) fraction elevation after successful percutaneous coronary intervention in a native coronary artery. Based on peak CK-MB levels measured after intervention, patients were divided into 3 groups: no elevation (group 1, n = 184), 1 to 3 × upper normal levels (group 2, n = 72), and >3 × upper normal levels (group 3, n = 70). Baseline clinical and angiographic characteristics were similar among the 3 groups. Angiographic success was similar among the 3 groups, although there was a significantly higher use of intra-aortic balloon pump in patients who had postprocedural CK-MB >3 × normal values and a higher rate of in-hospital complications, i.e., repeat catheterization, repeat target lesion intervention, pulmonary edema, renal function deterioration, emergency dialysis, and major bleeding complications. At 1-year follow-up, mortality rates were significantly higher in these patients (35.4% vs 22.0% for patients with CK-MB 1 to 3 × normal values and 16.7% for patients without CK-MB elevation, p = 0.007). Multivariate analysis showed that CK-MB >3 × normal (odds ratio 3.04; 95% confidence interval 1.41 to 6.57, p = 0.005) and intra-aortic balloon pump (odds ratio 1.49; confidence interval 1.15 to 1.93, p = 0.002) were independent predictors of late mortality. Therefore, patients with chronic renal failure who had CK-MB elevation >3 × the upper normal limit after a successful percutaneous coronary intervention had a higher incidence of in-hospital complications and a significantly higher mortality rate at 1-year follow-up than patients without CK-MB elevation or with <3 × normal CK-MB elevation.

Comparison of hemodynamic effects of enhanced external counterpulsation and intra-aortic balloon pumping in patients with acute myocardial infarction

This study compared the hemodynamic effects of enhanced external counterpulsation and intra-aortic counterpulsation in patients with acute myocardial infarction. Results demonstrated similarity between these 2 methods, except enhanced external counterpulsation had a transient effect of increasing right atrial pressure, pulmonary capillary wedge pressure, and cardiac index.

Vascular complications of the intraaortic balloon pump in patients undergoing open heart operations: 15-year experience

Background. The beneficial effects of the intraaortic balloon pump (IABP) in providing circulatory support must be weighed against its complications, particularly its vascular trauma. Methods. Five hundred nine patients who underwent open heart operations at our institution and who were treated with the IABP from January 1980 through December 1994 were studied retrospectively to assess IABP-related vascular complications and their independent preoperative predictors and the implications of IABP-related vascular complications on the patients’ mortality, morbidity (clinical sepsis and organ failure), and long-term survival. Results. Early vascular complications occurred in 56 patients (11%) and major complications occurred in 41 patients (8%). The latter consisted of aortic perforation in 1 patient, aortoiliac dissection in 2 patients, and limb ischemia in 38 patients. Logistic regression analysis identified concomitant peripheral vascular disease ( p < 0.001), elevated preoperative end-diastolic pressure, small body surface area, and large catheter size ( p < 0.05) as independent risk factors for IABP-related major vascular complications in patients who survived the day of operation. Late IABP-related sequelae occurred in 10 patients, 9 of whom had had early vascular complications. The presence of vascular complications per se was not a significant independent factor among other risk factors for mortality, morbidity, or long-term survival. Conclusions. Careful clinical assessment of the aortofemoral vascular tree is a cornerstone of early diagnosis and early intervention and usually prevents limb loss. The significant decrease in major vascular complications that has occurred over the last 5 years can be explained by the increased use of catheters with smaller diameters. The timing of IABP insertion in relation to operation and the duration of IABP use were the only device-related risk factors identified for morbidity and survival.

Aortic function in patients during intra-aortic balloon pumping determined by the pressure-diameter relation

Objective: The physiologic basis for the hemodynamic and clinical improvement achieved by the use of intra-aortic balloon pumping in patients with cardiogenic shock has not been clarified in all its aspects. This study evaluated the possible contribution of pump-induced alterations of aortic mechanics to the overall benefit gained by the implementation of this therapeutic modality in patients with acute heart failure of ischemic origin. Methods: The aortic pressure-diameter relation was obtained by use of an intravascular catheter for aortic diameter measurements developed in our institution and previously validated, simultaneously with a catheter-tip micromanometer for aortic pressure measurements at the same aortic level. Aortic function indices were compared before and during intra-aortic balloon pumping in 12 patients with cardiogenic shock. Results: Intra-aortic balloon pumping increased cardiac index and aortic distensibility by 24% and 30%, respectively, and reduced myocardial oxygen demand by 31% ( P < .001 for all alterations). Energy loss caused by aortic wall viscosity increased by 207% ( P < .001). The aortic diameter augmentation index increased by 68% ( P < .001); the aortic pressure augmentation index decreased by 117% ( P < .001). Linear regression analysis showed that cardiac index and myocardial oxygen demand were related with the aortic stiffness constant both before and during intra-aortic balloon pumping. Conclusions: During intra-aortic balloon pumping, aortic distensibility was improved, and wave reflection from the arterial periphery was reduced. The relationship between cardiac index and myocardial oxygen demand and aortic stiffness suggests that improvement of the elastic properties of the aorta was an important mechanism by which intra-aortic balloon pumping improved circulatory function. (J Thorac Cardiovasc Surg 1998;116:1052-9)

Liberal use of intra-aortic balloon pumping in patients undergoing coronary bypass surgery

The intra-aortic balloon pump (IABP) is an effective, minimally invasive cardiac assist device which can be used perioperatively to increase survival after cardiac surgery. Surgeons vary according to how aggressively they use IABP. Some prefer to use increased doses of inotropic drugs in the first instance. From August 1990 to February 1993, 38 of 480 consecutive patients having cardiac surgery for ischaemic heart disease (IHD) had perioperative insertion of the IABP (usage rate 7.9%). There was a low threshold for its use, with some IABPs being placed in patients prophylactically in the operating theatre if postoperative low cardiac output was anticipated. Generally, if inotropic medication was required (greater than renal dosage dopamine) when the patient left the operating theatre, the IABP was inserted, and an attempt made to minimise inotropic medication. The IABP was more commonly inserted for complex coronary cases (40% of 55 patients) than when a primary coronary artery bypass graft (CABG) was performed (3.8% of 425 patients). The early mortality overall was 1 % and in the IABP group was 5.3%. There were 2 late deaths. IABP-related morbidity was infrequent (one false aneurysm of femoral artery requiring repair, one burst balloon requiring open removal via a groin incision). Complications were more commonly patient related. Using this approach, the mortality was 3.6% for complex coronary surgery and 0.7% for first time CABG. Inotropic medication was required in only 10% of patients, and in 68% of these, low dosage only was necessary.