Intra-aortic Balloon Pump Counterpulsation Research Articles

Rapid complete reversal of systemic hypoperfusion after intra-aortic balloon pump counterpulsation and survival in cardiogenic shock complicating an acute myocardial infarction

In patients with cardiogenic shock (CS) complicating an acute myocardial infarction, a strategy of early revascularization (ERV) versus initial medical stabilization (IMS) improves survival. Intra-aortic balloon counterpulsation (IABC) provides hemodynamic support and facilitates coronary angiography and revascularization in CS patients. We evaluated 499 patients with record of systemic hypoperfusion status as an early response to IABC from the SHOCK trial (n = 185) and registry (n = 314) to determine the association between rapid complete reversal of systemic hypoperfusion (CRH) after 30 minutes of IABC and in-hospital, 30-day and 1-year mortality. Rapid complete reversal of systemic hypoperfusion was highly associated with lower in-hospital mortality (29% versus 65%, P < .001) in all patients. In the SHOCK trial, among patients assigned to ERV versus IMS, 30-day mortality was 26% versus 29%, respectively, with CRH and 61% versus 81%, respectively, without CRH after commencing IABC. The corresponding 1-year mortality rates were 35% versus 52% for ERV and 69% versus 87% for IMS (interaction P ≥ .25 at both time points). After adjusting for important correlates of outcome (left ventricular ejection fraction, age, and randomization to ERV), a significant association remained between CRH and registry and trial in-hospital mortality (odds ratio 0.23, 95% CI 0.14-0.39, P < .001) and trial 1-year mortality (odds ratio .28, 95% CI 0.12-0.67, P < .001). In CS patients, CRH after commencing IABC was independently associated with improved in-hospital, 30-day and 1-year survival regardless of early revascularization. In CS patients, CRH with IABC is an important early prognostic feature.

Mechanical Assistance by Intra‐Aortic Balloon Pump Counterpulsation During Reperfusion Increases Coronary Blood Flow and Mitigates the No‐Reflow Phenomenon: An Experimental Study

The effects of the intra-aortic balloon pump (IABP) counterpulsation on the extent of myocardial infarction (MI), the no-reflow phenomenon (NRP), and coronary blood flow (CBF) during reperfusion in an ischemia-reperfusion experimental model have not been clarified. Eleven pigs underwent occlusion of the mid left anterior descending coronary artery for 1 h, followed by reperfusion for 2 h. CBF, distal to the occlusion site, was measured. In six experiments, IABP support began 10 min before, and continued throughout reperfusion (IABP Group). Five pigs without IABP support served as controls. At the end of each experiment, the myocardial area at risk (MAR) of infarction and the extent of MI and NRP were measured. Hemodynamic measurements at baseline and during coronary occlusion were similar in both groups. During reperfusion, systolic aortic blood pressure was significantly lower in the IABP Group than in controls. In the IABP Group, CBF reached a peak at 5 min of reperfusion, gradually decreased, but remained higher than at baseline, and significantly higher than in controls throughout the 2 h of reperfusion. In controls, CBF increased significantly above baseline immediately after the onset of reperfusion, then returned to baseline within 90 min. The extent of NRP (37 ± 25% vs. 68 ± 17%, P = 0.047) and MI (39 ± 23% vs. 67 ± 13%, P = 0.036), both expressed as percentage of MAR, was significantly less in the IABP group than in controls. After prolonged myocardial ischemia, IABP assistance started just 10 min before and throughout reperfusion increased CBF and limited infarct size and extent of NRP.

Management of Unstable Arrhythmias in Cardiogenic Shock

Atrial and ventricular arrhythmias commonly arise in the setting of cardiogenic shock and often result in hemodynamic deterioration. Causative factors include myocardial ischemia, volume overload, and metabolic disturbances. Correcting these factors plays an important role in managing arrhythmias in this setting. Ventricular arrhythmias are more ominous compared to atrial arrhythmias but both require prompt intervention with electrical shock and anti-arrhythmic drug suppression. Coronary reperfusion is key to improving survival, including reducing the risk of sudden cardiac arrest, in acute myocardial infarction. Case series have also demonstrated the value of intra-aortic balloon pump counter-pulsation in suppressing ventricular arrhythmias in cardiogenic shock. The mechanism of arrhythmia suppression may be due to improved coronary perfusion and afterload reduction. Percutaneous ventricular assist device placement may be effective in this setting; however, data addressing this specific endpoint are lacking. Anti-arrhythmic drug options for ventricular and atrial arrhythmia suppression, in the setting of cardiogenic shock, are relatively limited. Common class I agents are excluded due to the inherent abnormal cardiac structure and function in the setting of cardiogenic shock. Class III drug options include dofetilide and amiodarone. The other Class III agents, sotalol and dronedarone, are excluded due to associated mortality observed in the SWORD and ANDROMEDA trials, respectively. Dofetilide is renally excreted and causes QT interval prolongation. Care should be taken to avoid excessive drug accumulation due to poor kidney perfusion and function. Dofetilide is approved for use for atrial arrhythmias and has not been studied for ventricular arrhythmia suppression. The DIAMOND-CHF trial established its safety in the setting of heart failure. Amiodarone is very effective in suppressing both atrial and ventricular arrhythmias. It is often the drug of choice in heart failure. Its off-label use for atrial arrhythmias is very common. Care should be taken with intravenous amiodarone to avoid hypotension.

Wave energy patterns of counterpulsation: A novel approach with wave intensity analysis

In counterpulsation, diastolic augmentation increases coronary blood flow and systolic unloading reduces left ventricular afterload. We present a new approach with wave intensity analysis to revisit and explain counterpulsation principles. In an acute porcine model, a standard intra-aortic balloon pump was placed in descending aorta in 4 pigs. We measured pressure and velocity with probes in left anterior descending artery and aorta during and without intra-aortic balloon pump assistance. Wave intensities of aortic and left coronary waves were derived from pressure and flow measurements with synchronization correction. We identified predominating waves in counterpulsation. In the aorta, during diastolic augmentation, intra-aortic balloon inflation generated a backward compression wave, with a "pushing" effect toward the aortic root that translated to a forward compression wave into coronary circulation. During systolic unloading, intra-aortic balloon pump deflation generated a backward expansion wave that "sucked" blood from left coronary bed into the aorta. While this backward expansion wave translated to reduced left ventricular afterload, the "sucking" effect resulted in left coronary blood steal, as demonstrated by a forward expansion wave in left anterior descending coronary flow. The waves were sensitive to inflation and deflation timing, with just 25 ms delay from standard deflation timing leading to weaker forward expansion wave and less coronary regurgitation. Intra-aortic balloon pumps generate backward-traveling waves that predominantly drive aortic and coronary blood flow during counterpulsation. Wave intensity analysis of arterial circulations may provide a mechanism to explain diastolic augmentation and systolic unloading of intra-aortic balloon pump counterpulsation.

Supported percutaneous coronary intervention using a novel 6‐Fr intra‐aortic balloon pump catheter via the brachial artery in a nonagenarian patient with an abdominal aortic aneurysm

Intra-aortic balloon pump (IABP) counterpulsation is a useful hemodynamic assist device during complex percutaneous coronary intervention (PCI) in patients with poor left ventricular function; however, the presence of an abdominal aortic aneurysm poses a problem, because insertion via the femoral artery may cause distal embolism and aneurysm rupture. A 92-year-old man with unstable angina was admitted to our hospital. Coronary angiography revealed chronic total occlusion of the proximal left anterior descending artery and severe stenosis of the left circumflex artery (LCX). The left ventricular ejection fraction was 36%. He also had an infrarenal abdominal aortic aneurysm with a diameter of 55 mm. Supported PCI was performed for the management of the LCX lesion. A novel 6-Fr IABP catheter was inserted via the left brachial artery. The lesion was successfully dilated, and a 3.0 × 13 mm Cypher® stent was placed. After the PCI procedure, the IABP catheter was retrieved in the catheter laboratory, and the patient was discharged after 7 days. When a femoral approach is contraindicated in PCI, 6-Fr IABP catheter insertion via the brachial artery is feasible and effective.

Encouraging survival rates in patients with acute myocardial infarction treated with an intra-aortic balloon pump.

ObjectiveTo evaluate a 30-day and long-term outcome of patients with acute myocardial infarction (AMI) treated with intra-aortic balloon pump (IABP) counterpulsation and to identify predictors of a 30-day and long-term all-cause mortality.MethodsRetrospective cohort study of 437 consecutive AMI patients treated with IABP between January 1990 and June 2004. A Cox proportional hazards model was used to identify predictors of a 30-day and long-term all-cause mortality.ResultsMean age of the study population was 61 ± 11 years, 80% of the patients were male, and 68% had cardiogenic shock. Survival until IABP removal after successful haemodynamic stabilisation was 78% (n = 341). Cumulative 30-day survival was 68%. Median follow-up was 2.9 years (range, 6 months to 15 years). In patients who survived until IABP removal, cumulative 1-, 5-, and 10-year survival was 75%, 61%, and 39%, respectively. Independent predictors of higher long-term mortality were prior cerebrovascular accident (hazard ratio (HR), 1.8; 95% confidence interval (CI), 1.0–3.4), need for antiarrhythmic drugs (HR, 2.3; 95% CI, 1.5–3.3), and need for renal replacement therapy (HR, 2.3; 95% CI, 1.2–4.3). Independent predictors of lower long-term mortality were primary percutaneous coronary intervention (PCI; HR, 0.6; 95% CI, 0.4–1.0), failed thrombolysis with rescue PCI (HR, 0.5; 95% CI, 0.3–0.9), and coronary artery bypass grafting (HR, 0.3; 95% CI, 0.1–0.5).ConclusionsDespite high in-hospital mortality in patients with AMI treated with IABP, a favourable number of patients survived in the long-term. These results underscore the value of aggressive haemodynamic support of patients throughout the acute phase of AMI.

Acute and critically ill peripartum cardiomyopathy and 'bridge to' therapeutic options: a single center experience with intra-aortic balloon pump, extra corporeal membrane oxygenation and continuous-flow left ventricular assist devices

IntroductionPeripartum cardiomyopathy (PPCM) patients refractory to medical therapy and intra-aortic balloon pump (IABP) counterpulsation or in whom weaning from these therapies is impossible, are candidates for a left ventricular assist device (LVAD) as a bridge to recovery or transplant. Continuous-flow LVADs are smaller, have a better long-term durability and are associated with better outcomes. Extra corporeal membrane oxygenation (ECMO) can be used as a temporary support in patients with refractory cardiogenic shock. The aim of this study was to evaluate the efficacy and safety of mechanical support in acute and critically ill PPCM patients.MethodsThis was a retrospective search of the patient database of the Ghent University hospital (2000 to 2010).ResultsSix PPCM-patients were treated with mechanical support. Three patients presented in the postpartum period and three patients at the end of pregnancy. All were treated with IABP, the duration of IABP support ranged from 1 to 13 days. An ECMO was inserted in one patient who presented with cardiogenic shock, multiple organ dysfunction syndrome and a stillborn baby. Two patients showed partial recovery and could be weaned off the IABP. Four patients were implanted with a continuous-flow LVAD (HeartMate II®, Thoratec Inc.), including the ECMO-patient. Three LVAD patients were successfully transplanted 78, 126 and 360 days after LVAD implant; one patient is still on the transplant waiting list. We observed one peripheral thrombotic complication due to IABP and five early bleeding complications in three LVAD patients. One patient died suddenly two years after transplantation.ConclusionsIn PPCM with refractory heart failure IABP was safe and efficient as a bridge to recovery or as a bridge to LVAD. ECMO provided temporary support as a bridge to LVAD, while the newer continuous-flow LVADs offered a safe bridge to transplant.

Haemodynamic Support Devices for Complex and High-risk Percutaneous Coronary Intervention

Patients at high risk, such as those with marked left ventricular dysfunction, acute coronary syndromes with unstable haemodynamics and arrhythmias, as well as single target vessels that supply a large area of myocardium, are undergoing percutaneous coronary intervention (PCI) with increasing frequency. Percutaneous haemodynamic support devices, including intra-aortic balloon counterpulsation pumps, percutaneous cardiopulmonary support and left ventricular assist devices, have been developed as adjunctive therapies during these complex procedures. Improvements in haemodynamic profiles with the use of these devices enhance procedural safety, allowing successful PCI to be performed in a more stable environment. Nevertheless, the use of these devices is associated with potentially serious complications and solid evidence for their routine use in high-risk PCI is lacking. Ongoing improvements in device designs and deployment techniques may eventually allow earlier, prophylactic use of support devices. Until then, the use of haemodynamic support devices should be individualised after careful consideration of the potential benefits and risks involved.

Prophylactic IABPs not needed in PCI

Intra-aortic balloon counterpulsation pumps (IABPs) are efficacious in treating cardiogenic shock and are often inserted prophylactically in hemodynamically stable patients who are undergoing high-risk percutaneous coronary intervention (PCI). However, in contrast to previous findings from several retrospective observational studies, a randomized controlled trial has now demonstrated that prophylactic insertion of IABPs during high-risk PCI is not associated with a reduction in the incidence of major adverse cardiac and cardiovascular events (MACCE).

The Percutaneous Ventricular Assist Device in Severe Refractory Cardiogenic Shock

We evaluated the efficacy and safety of the percutaneous ventricular assist device (pVAD) in patients in severe refractory cardiogenic shock (SRCS) despite intra-aortic balloon pump (IABP) and/or high-dose vasopressor support. SRCS is associated with substantial mortality despite IABP counterpulsation. Until recently, there was no rapid, minimally invasive means of providing increased hemodynamic support in SRCS. A total of 117 patients with SRCS implanted with TandemHeart pVAD (CardiacAssist, Inc., Pittsburgh, Pennsylvania) were studied, of whom 56 patients (47.9%) underwent active cardiopulmonary resuscitation immediately before or at the time of implantation. Data was collected regarding clinical characteristics, hemodynamics, and laboratory values. Eighty patients had ischemic and 37 patients had nonischemic cardiomyopathy. The average duration of support was 5.8 ± 4.75 days. After implantation, the cardiac index improved from median 0.52 (interquartile range [IQR]: 0.8) l/(min·m(2)) to 3.0 (IQR:0.9) l/(min·m(2)) (p < 0.001). The systolic blood pressure and mixed venous oxygen saturation increased from 75 (IQR:15) mm Hg to 100 (IQR:15) mm Hg (p < 0.001) and 49 (IQR:11.5) to 69.3 (IQR:10) (p < 0.001), respectively. The urine output increased from 70.7 (IQR: 70) ml/day to 1,200 (IQR: 1,620) ml/day (p < 0.001). The pulmonary capillary wedge pressure, lactic acid level, and creatinine level decreased, respectively, from 31.53 ± 10.2 mm Hg to 17.29 ± 10.82 mm Hg (p < 0.001), 24.5 (IQR: 74.25) mg/dl to 11 (IQR: 92) mg/dl (p < 0.001), and 1.5 (IQR: 0.95) mg/dl to 1.2 (IQR: 0.9) mg/dl (p = 0.009). The mortality rates at 30 days and 6 months were 40.2% and 45.3%, respectively. The pVAD rapidly reversed the terminal hemodynamic compromise seen in patients with SRCS refractory to IABP and vasopressor support.

Treatment of Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy (TC) is a condition most prevalent in postmenopausal women, characterized by transient left ventricular dysfunction following acute emotional or physical stress. Direct catecholamine-mediated myocyte injury and microvascular dysfunction leading to myocardial stunning are believed to play a major role in its pathogenesis. The treatment of TC remains empirical. In the acute phase, therapy must be individualized depending on hemodynamic situation. In stable conditions, it appears advantageous to prevent excessive sympathetic activation by combining alpha and beta blockade. Beta blockers are used to treat dynamic left ventricular obstruction. Phenylephrine may represent an alternative approach in patients presenting with outflow tract obstruction and severe hypotension. In hemodynamically unstable patients, early administration of intra-aortic balloon pump counterpulsation should be considered. As no consensus currently exists with respect to the chronic management of TC, randomized clinical trials are urgently needed with focus on treatment strategies.

Comparison of Hospital Mortality With Intra-Aortic Balloon Counterpulsation Insertion Before vs After Primary Percutaneous Coronary Intervention for Cardiogenic Shock Complicating Acute Myocardial Infarction

Abstract. Primary percutaneous coronary intervention (PCI) and intra-aortic balloon pump counterpulsation (IABP) are established treatment modalities in acute myocardial infarction complicated by cardiogenic shock. We hypothesized that the insertion of the IABP before primary PCI might result in better survival of patients with cardiogenic shock compared with postponing the insertion until after primary PCI. We, therefore, retrospectively studied 48 patients who had undergone primary PCI with IABP because of cardiogenic shock complicating acute myocardial infarction (26 patients received the IABP before and 22 patients after primary PCI). No significant differences were present in the baseline clinical characteristics between the 2 groups. The mean number of diseased vessels was greater in the group of patients treated with the IABP before primary PCI (2.8±0.5 vs 2.3±0.7, P=.012), but the difference in the number of treated vessels was not significant. The peak creatine kinase and creatine kinase-MB levels were lower in patients treated with the IABP before primary PCI (median, 1077; interquartile range, 438–2067 vs median, 3299; interquartile range, 695–6834; P=.047 and median, 95; interquartile range, 34–196 vs median, 192; interquartile range, 82–467; P=.048, respectively). In-hospital mortality and the overall incidence of major adverse cardiac and cerebrovascular events were significantly lower in the group of patients receiving the IABP before primary PCI (19% vs 59% and 23% vs 77%, P=.007 and P=.0004, respectively). Multivariate analysis identified renal failure (odds ratio, 15.2; 95% confidence interval, 3.13–73.66) and insertion of the IABP after PCI (odds ratio, 5.2; 95% confidence interval, 1.09–24.76) as the only independent predictors of in-hospital mortality. In conclusion, the results of the present study suggest that patients with cardiogenic shock complicating acute myocardial infarction who undergo primary PCI assisted by IABP have a more favorable in-hospital outcome and lower in-hospital mortality than patients who receive IABP after PCI. Abdel-Wahab M, Saad M, Kynast J, et al. Comparison of hospital mortality with intra-aortic balloon counterpulsation insertion before versus after primary percutaneous coronary intervention for cardiogenic shock complicating acute myocardial infarction. Am J Cardiol. 2010;105:967–971.

Cardiogenic Shock Complicating Subarachnoid Haemorrhage Diagnosed as Tako Tsubo Cardiomyopathy: A Cautionary Tale

Tako Tsubo or "stress" cardiomyopathy and its variants are well recognised as potential causes of acute coronary presentations, with manifestations including chest pain, cardiac failure and arrhythmia. Similarly, subarachnoid haemorrhage may be associated with cardiac abnormalities. Tako Tsubo cardiomyopathy is a diagnosis of exclusion with typical left ventricular dysfunction in the absence of epicardial coronary disease, but importantly also after exclusion of an intracerebral insult. We describe a case of unrecognised intracerebral haemorrhage with left ventricular dysfunction consistent with both variant Tako Tsubo cardiomyopathy and subarachnoid haemorrhage in a patient treated with intra-aortic balloon pump counterpulsation and associated heparinisation.

Intra-Aortic Balloon Pump Counterpulsation in the Setting of Subarachnoid Hemorrhage, Cerebral Vasospasm, and Neurogenic Stress Cardiomyopathy. Case Report and Review of the Literature

The management of symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH) can be often complicated by the presence of stunned myocardium and left ventricular failure. Vasopressors and inotropes are commonly used to optimize mean arterial pressure (MAP) and cerebral perfusion pressure (CPP). Intra-aortic balloon counterpulsation pump (IABP) may be indicated in the management of these patients. We report the case of a 55-year-old patient who suffered an aSAH complicated by severe left ventricular failure, who subsequently developed symptomatic cerebral vasospasm. Left ventricular failure precluded traditional hemodynamic augmentation, and IABP was successfully used instead, which allowed for reinstitution of hypertensive hypervolemic therapy and prevented delayed cerebral ischemia. A review of the literature conducted on symptomatic cerebral vasospasm after aSAH and severe left ventricular failure revealed seven publications describing 14 patients with aSAH treated with an IABP during the period of vasospasm. Intra-aortic balloon counterpulsation pump (IABP) is used for hemodynamic support of patients in cardiogenic shock and its use in the setting of aSAH, cardiomyopathy, and cerebral vasospasm can be beneficial in preventing delayed ischemic deficits.

Comparison of Hospital Mortality With Intra-Aortic Balloon Counterpulsation Insertion Before Versus After Primary Percutaneous Coronary Intervention for Cardiogenic Shock Complicating Acute Myocardial Infarction

Primary percutaneous coronary intervention (PCI) and intra-aortic balloon pump counterpulsation (IABP) are established treatment modalities in acute myocardial infarction complicated by cardiogenic shock. We hypothesized that the insertion of the IABP before primary PCI might result in better survival of patients with cardiogenic shock compared to postponing the insertion to after primary PCI. We, therefore, retrospectively studied 48 patients who had undergone primary PCI with IABP because of cardiogenic shock complicating acute myocardial infarction (26 patients received the IABP before and 22 patients after primary PCI). No significant differences were present in the baseline clinical characteristics between the 2 groups. The mean number of diseased vessels was greater in the group of patients treated with the IABP before primary PCI (2.8 +/- 0.5 vs 2.3 +/- 0.7, p = 0.012), but the difference in the number of treated vessels was not significant. The peak creatine kinase and creatine kinase -MB levels were lower in patients treated with the IABP before primary PCI (median 1,077, interquartile range 438 to 2067 vs median 3,299, interquartile range 695 to 6,834, p = 0.047, and median 95, interquartile range 34 to 196 vs median 192, interquartile range 82 to 467, p = 0.048, respectively). In-hospital mortality and the overall incidence of major adverse cardiac and cerebrovascular events were significantly lower in the group of patients receiving the IABP before primary PCI (19% vs 59% and 23% vs 77%, p = 0.007 and p = 0.0004, respectively). Multivariate analysis identified renal failure (odds ratio 15.2, 95% confidence interval 3.13 to 73.66) and insertion of the IABP after PCI (odds ratio 5.2, 95% confidence interval 1.09 to 24.76) as the only independent predictors of in-hospital mortality. In conclusion, the results of the present study suggest that patients with cardiogenic shock complicating acute myocardial infarction who undergo primary PCI assisted by IABP have a more favorable in-hospital outcome and lower in-hospital mortality than patients who receive IABP after PCI.

Intra-aortic balloon counterpulsation in patients with acute myocardial infarction complicated by cardiogenic shock: The prospective, randomized IABP SHOCK Trial for attenuation of multiorgan dysfunction syndrome*

Patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction with cardiogenic shock (CS) are often treated with intra-aortic balloon pump counterpulsation (IABP), even though the evidence to support this is limited. We determined whether IABP as an addition to PCI-centered therapy ameliorates multiorgan dysfunction syndrome (MODS) in patients with acute myocardial infarction complicated by CS. A prospective, randomized, controlled, open-label clinical trial recruiting patients between March 2003 and June 2004 (ClinicalTrials.gov ID NCT00469248). Tertiary care university hospital. Forty-five consecutive patients with AMI and CS undergoing PCI were randomized to treatment with or without IABP. Acute Physiology and Chronic Health Evaluation (APACHE) II scores (primary outcome measure), hemodynamic values, inflammatory markers, and plasma brain natriuretic peptide (BNP) levels (secondary outcomes) were collected over 4 days from randomization. The prospective hypothesis was that adding IABP therapy to "standard care" would improve CS-triggered MODS. The addition of IABP to standard therapy did not result in a significant improvement in MODS (measured by serial APACHE II scoring over 4 days). IABP use had no significant effect on cardiac index or systemic inflammatory activation, although BNP levels were significantly lower in IABP-treated patients. Initial and serial APACHE II scoring correlated with mortality better than cardiac index, systemic inflammatory state, and BNP levels in this group of patients. Nonsurvivors had significantly higher initial APACHE II scores (29.9 +/- 2.88) than survivors (18.1 +/- 1.66, p < .05). Nevertheless, discrepancies among patients within the groups cannot be ruled out and might interfere with our results. In this randomized trial addressing addition of IABP in CS patients, mechanical support was associated only with modest effects on reduction of APACHE II score as a marker of severity of disease, improvement of cardiac index, reduction of inflammatory state, or reduction of BNP biomarker status compared with medical therapy alone. However, the limitations of our present trial preclude any definitive conclusion, but request for a larger prospective, randomized, multicentered trial with mortality as primary end point.

Clinical Implications of Thrombocytopenia Among Patients Undergoing Intra‐aortic Balloon Pump Counterpulsation in the Coronary Care Unit

Thrombocytopenia Hypothesis: intra-aortic balloon pump (IABP)-associated thrombocytopenia is not associated with an increased risk of major bleeding or in-hospital death. Thrombocytopenia is a common adverse effect of the IABP. However, the clinical implications of IABP-associated thrombocytopenia are unknown. We assessed the incidence and predictors of thrombocytopenia, and the association between thrombocytopenia and relevant clinical end points, using prospectively collected data on 252 consecutive patients undergoing IABP in a single coronary care unit (CCU). Anticoagulation with intravenous heparin was administered to 182 patients (72%). Baseline platelet counts were 232 000 +/- 96 000 mL, decreased to 154 000 +/- 74 000 mL at day 3, and recovered to baseline by day 8. Thrombocytopenia (nadir < 150 000 mL or > 50% reduction from baseline) occurred in 109 patients (43%), with a similar incidence among patients who received heparin and those who did not (45% vs 40%, P = 0.5). Independent predictors of thrombocytopenia were lower body weight, cardiogenic shock, and duration of IABP support. The incidence of both major bleeding and in-hospital death were higher among patients who developed thrombocytopenia than among those who did not (13.8% vs 4.2%, P = 0.01 and 28% vs 16%, P = 0.02, respectively). However, after controlling for confounding variables, thrombocytopenia was not an independent predictor of either major bleeding (odds ratio [OR]: 2.2, 95% confidence interval [CI]: 0.8-6.4, P = 0.1) or in-hospital death (OR: 1.5, 95% CI: 0.8-2.9, P = 0.3). Among patients undergoing IABP in the CCU, thrombocytopenia is generally mild, appears to be unrelated to concomitant heparin use, and is not associated with an increased risk of major bleeding or in-hospital death.

Prognosis of patients undergoing cardiac surgery and treated with intra-aortic balloon pump counterpulsation prior to surgery: a long-term follow-up study

The aim of this study was to evaluate short- and long-term outcome in patients undergoing coronary artery bypass grafting (CABG), who received an intra-aortic balloon pump (IABP) prior to surgery. Between January 1990 and June 2004, all patients (n=154) who received an IABP prior to on-pump CABG in our center were included. Patients received the IABP for vital indications (i.e. either unstable angina refractory to medical therapy or cardiogenic shock; group 1: n=99) or for prophylactic reasons (group 2: n=55). A Cox proportional hazards model was used to identify predictors of long-term all-cause mortality. Compared with the EuroSCORE predictive model, observed 30-day mortality in group 1 (15.2%) was slightly higher than predicted (10.3%). A decrease in 30-day mortality occurred in group 2 (median predicted mortality was 7.2% and observed was 0%). Cumulative 1-, 5-, and 6-year survival was 82.8+/-3.8%, 70.1+/-4.9%, and 67.3+/-5.1% for group 1 vs. 98.2+/-1.8%, 84.0+/-5.6% and 84.0+/-5.6% for group 2 (Log-rank: P=0.02). Logistic EuroSCORE (HR 1.03 [1.01-1.05], P=0.007) was an independent predictor of long-term all-cause mortality.

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

Percutaneous left ventricular assist devices vs. intra-aortic balloon pump counterpulsation for treatment of cardiogenic shock: a meta-analysis of controlled trials

Studies have compared safety and efficacy of percutaneous left ventricular assist devices (LVADs) with intra-aortic balloon pump (IABP) counterpulsation in patients with cardiogenic shock. We performed a meta-analysis of controlled trials to evaluate potential benefits of percutaneous LVAD on haemodynamics and 30-day survival. Two independent investigators searched Medline, Embase, and Cochrane Central Register of Controlled Trials for all controlled trials using percutaneous LVAD in patients with cardiogenic shock, where after data were extracted using standardized forms. Weighted mean differences (MDs) were calculated for cardiac index (CI), mean arterial pressure (MAP), and pulmonary capillary wedge pressure (PCWP). Relative risks (RRs) were calculated for 30-day mortality, leg ischaemia, bleeding, and sepsis. In main analysis, trials were combined using inverse-variance random effects approach. Two trials evaluated the TandemHeart and a recent trial used the Impella device. After device implantation, percutaneous LVAD patients had higher CI (MD 0.35 L/min/m(2), 95% CI 0.09-0.61), higher MAP (MD 12.8 mmHg, 95% CI 3.6-22.0), and lower PCWP (MD -5.3 mm Hg, 95% CI -9.4 to -1.2) compared with IABP patients. Similar 30-day mortality (RR 1.06, 95% CI 0.68-1.66) was observed using percutaneous LVAD compared with IABP. No significant difference was observed in incidence of leg ischaemia (RR 2.59, 95% CI 0.75-8.97) in percutaneous LVAD patients compared with IABP patients. Bleeding (RR 2.35, 95% CI 1.40-3.93) was significantly more observed in TandemHeart patients compared with patients treated with IABP. Although percutaneous LVAD provides superior haemodynamic support in patients with cardiogenic shock compared with IABP, the use of these more powerful devices did not improve early survival. These results do not yet support percutaneous LVAD as first-choice approach in the mechanical management of cardiogenic shock.