Intra-aortic balloon pump in intensive cardiac care: A registry in Florence

Abstract

The Intra-aortic Balloon Pump (IABP) is currently the most commonly used mechanical assist device to improve and support hemodynamics in patients with cardiogenic shock; it is widely used also in high-risk patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) [1–9]. However, the impact of IABP on prognosis is so far controversial [5,10]. We assessed the in-hospital mortality and complications in patients treated with IABP consecutively admitted to our Intensive Cardiac Care Unit (ICCU). From Jan. 1, 2005 to Dec. 31, 2008, 3500 patients were consecutively admitted to our ICCU [11–13]. Among them, 414 (11.8%) underwent IABP during their hospitalization and were prospectively enrolled in our Registry. Large ischemic risk area (LIRA)was defined as “ejection fraction less than 40% together with proximal occlusion of left descending anterior coronary artery associated or not with critical lesions in other coronary arteries”. In these patients IABP was deployed after PCI. Patients were defined as “high risk” as if one ormore of the following criteria were present: ventricular ejection fraction (LVEF)<40%, killip class 3, persistent malignant ventricular arrhythmias, acute mitral regurgitation and severe coronary artery disease (left main stem or three vessel or vein graft disease). Major bleeding.Major bleeding was defined according to Replace 2 [14]: Continuous data (Kolmogorov–Smirnov test ) were expressed as mean±SD, categorical data as frequencies and percentages. All data were analysed by means of Fisher's exact test or Student's t test, when appropriate. Variables resulted significantly different between subgroups were entered as covariates in a backward stepwise logistic regression analysis. A p<0.05 was considered statistical significant (SPSS 13.0 statistical software; SPSS Inc., Chicago, ILL, USA). The mean age of patients in the study was 68.5±11.4 years; 69.6% were men. Hypertension was detectable in 51.4% (n=213), dyslipidemia in 32.1% (n=133) and diabetes mellitus in 22.0% (n=91). About one fourth of patients (24.4%) showed prior myocardial infarction and prior PCI in the 20.5%. Table 1 shows indications for IABP in our series. In the majority of patients (67.1%, n=278) IABP was the only device, while in the remaining (32.9%) it was associated to other devices. The device most frequently associated with IABP was mechanical ventilation (41.7%; invasive: 24.6%; non-invasive 17.1%). The continuous veno-venous renal replacement therapy was used in 13.5% (n=56) of patients. Unfractioned heparin was used in 97.8% of patients. The majority of patients received dual antiplatelet therapy; acetylsalicylic acid (90.6%) and clopidogrel (83.8%). Therapy with glycoprotein IIb IIIa inhibitors was administered in 59.7% of cases. Inotropic agents (epinephrine, norepinephrine, dopamine and dobutamine) were used in 40.6% of patients, all with refractory cardiogenic shock. In our series, complications were 13.8% (57/414 patients) (Table 2). Thirtypatients (outof 57, 52.7.%) showed severebleeding, amongwhich half of patients exhibited unknown bleeding site while bleeding at the insertion site occurred in 12 patients. The incidence of IABP-related complications did not differ betweenmales and females (10.6%@versus 13.9% p=0.398). Patients who developed IABP-related complications showed a higher median duration of the device (48 h; 25–75th percentile 24–72 hversus 36 h;25–75thpercentile 24–48 h;p=0.007). In our population, 82 patients died (82/414:19.8%). Among patients who died, IABP was implanted because of: cardiogenic shock in 59 patients (72%), cardiac arrest in 8 patients (9.8%), periprocedural complications of PCI in 5 patients (6.1%), mechanical complication of acute myocardial infarction in 4 patients (4.9%), large ischemic risk area in 3 patients (3.6%), acute pulmonary edema in 2 patients (2.4%) and bridge to CABG in 1 patient (1.2%). Among the 47 patientswhodeveloped IABP-related complications 22 died; two deaths were due to IABP (intestinal ischemia in 1 patients and