Babak Azarbal

Cedars-Sinai Medical Center, Los Angeles, CA, USA

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Publications (10)80.1 Total impact

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    Article: Feasibility and safety of percutaneous coronary intervention in patients with end-stage liver disease referred for liver transplantation.
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    ABSTRACT: Percutaneous coronary intervention (PCI) has traditionally not been an option for patients with end-stage liver disease (ESLD) and coronary artery disease (CAD). This retrospective study was designed to demonstrate the feasibility and safety of PCI in liver transplant candidates. Patients with ESLD and hemodynamically significant CAD who were otherwise deemed to be acceptable candidates for liver transplantation underwent PCI. The procedural success rates, mortality and myocardial infarction rates, and bleeding outcomes were examined. Sixteen patients with ESLD underwent PCI: 15 with bare-metal stents (1.3 stents per patient on average) and 1 with balloon angioplasty alone. The median diameter stenosis per lesion was 80%, the median platelet count was 68 × 10(9) /L, the median international normalized ratio was 1.3, and the median Model for End-Stage Liver Disease score was 13. PCI was successful in 94% of the patients. One patient had a suboptimal residual stenosis of 50% after stenting. There were no in-hospital or 30-day deaths or myocardial infarctions, and no patients developed hematomas. One patient required a 1-U platelet transfusion, and another required 1 U of packed red blood cells. All patients remained clinically stable 1 month after PCI. Nine of the 16 patients were listed for liver transplantation, and 3 patients underwent liver transplantation. In conclusion, we have demonstrated the safety and feasibility of PCI in a small cohort of patients with ESLD and hemodynamically significant CAD, the majority of whom had significant thrombocytopenia. Larger studies are required to determine whether PCI is an effective treatment strategy for patients with ESLD and hemodynamically significant CAD who otherwise would not be candidates for liver transplantation.
    Liver Transplantation 03/2011; 17(7):809-13. · 3.39 Impact Factor
  • Article: Assessment of intermediate severity coronary lesions in the catheterization laboratory.
    Jonathan Tobis, Babak Azarbal, Leo Slavin
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    ABSTRACT: The management of intermediate coronary lesions, defined by a diameter stenosis of 40% to 70%, continues to be a therapeutic dilemma for cardiologists. The 2-dimensional representation of the arterial lesion provided by angiography is limited in distinguishing intermediate lesions that require stenting from those that simply need appropriate medical therapy. In the era of drug-eluting stents, some might propose that stenting all intermediate coronary lesions is an appropriate solution. However, the possibility of procedural complications such as coronary dissection, no reflow phenomenon, in-stent restenosis, and stent thrombosis requires accurate stratification of patients with intermediate coronary lesions to appropriate therapy. Intravascular ultrasound (IVUS) and fractional flow reserve index (FFR) provide anatomic and functional information that can be used in the catheterization laboratory to designate patients to the most appropriate therapy. The purpose of this review is to discuss the critical information obtained from IVUS and FFR in guiding treatment of patients with intermediate coronary lesions. In addition, the importance of IVUS and FFR in the management of patients with serial stenosis, bifurcation lesions, left main disease, saphenous vein graft disease, and acute coronary syndrome will be discussed.
    Journal of the American College of Cardiology 03/2007; 49(8):839-48. · 14.16 Impact Factor
  • Article: Percutaneous ventricular assist during aortic valvuloplasty: potential application to the deployment of aortic stent-valves.
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    ABSTRACT: We evaluated the short-term safety and efficacy of using the TandemHeart(R) percutaneous ventricular assist device in high-risk patients undergoing aortic valvuloplasty procedures. Aortic valvuloplasty was performed in 4 patients who had no ventricular assist device support and in 7 patients who used the TandemHeart for hemodynamic support. The age range was 65 to 94 years (mean, 83 +/- 11 yr). The mean ejection fraction was 0.30 +/- 0.14. A transseptal antegrade approach to the aortic valve was used in 8 patients and a retrograde approach in the remaining 3. WITH THE TANDEMHEART, ALL PROCEDURES WERE TECHNICALLY SUCCESSFUL: each patient survived at least 1 month after the procedure. The mean total balloon inflation time was 37 +/- 10 sec. The aortic valve area was 0.6 +/- 0.1 cm(2) before the procedure and 0.9 +/- 0.2 cm(2) afterwards (P=0.006). Without TandemHeart support, 1 patient died of cardiac arrest during the procedure. The mean total balloon inflation time was 11 +/- 3 sec. Aortic valve area was 0.6 +/- 0 cm(2) before the procedure and 1.1 +/- 0.3 cm(2) afterwards (P=0.3). No patient developed aortic regurgitation. We conclude that use of the TandemHeart for hemodynamic support during high-risk aortic valvuloplasty is associated with favorable intraprocedural and short-term outcomes. With the TandemHeart in place, balloon placement was precise, and inflation was maintained for up to 45 sec without balloon displacement. These attributes are essential during stent-valve placement, are achieved without rapid ventricular pacing, and may reduce the risk of global ischemia and death.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 02/2007; 34(1):36-40. · 0.65 Impact Factor
  • Article: Adverse events associated with nickel allergy in patients undergoing percutaneous atrial septal defect or patent foramen ovale closure.
    Journal of the American College of Cardiology 04/2006; 47(6):1226-7. · 14.16 Impact Factor
  • Article: Association of interatrial shunts and migraine headaches: impact of transcatheter closure.
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    ABSTRACT: To examine the relationship between patent foramen ovale (PFO) or atrial septal defect (ASD) with the incidence of migraine headache (MHA) and assess whether closure of the interatrial shunt in patients with MHA would result in improvement of MHA. Migraine headache is present in 12% of adults and has been associated with interatrial communications. This study examined the relationship between PFO or ASD with the incidence of MHA and assessed whether closure of the interatrial shunt in patients with MHA would result in improvement of MHA. A sample of 89 (66 PFO/23 ASD) adult patients underwent transcatheter closure of an interatrial communication using the CardioSEAL (n = 22), Amplatzer PFO (n = 43), or the Amplatzer ASD (n = 24) device. Before the procedure, MHA was present in 42% of patients (45% of patients with PFO and 30% of patients with ASD). At three months after the procedure, MHA disappeared completely in 75% of patients with MHA and aura and in 31% of patients with MHA without aura. Of the remaining patients, 40% had significant improvement (>or=2 grades by the Migraine Disability Assessment Questionnaire) of MHA. Transcatheter closure of PFO or ASD results in complete resolution of MHA in 60% of patients (75% of patients with migraine and aura) and improvement in symptoms in 40% of the remaining patients. Interatrial communications may play a role in the etiology of MHA either through paradoxic embolism or humoral factors that escape degradation in bypassing the pulmonary circulation. A randomized trial is needed to determine whether transcatheter closure of interatrial shunts is an effective treatment for MHA.
    Journal of the American College of Cardiology 03/2005; 45(4):489-92. · 14.16 Impact Factor
  • Article: Does patent foramen ovale promote cryptogenic stroke and migraine headache?
    M Jonathan Tobis, Babak Azarbal
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    ABSTRACT: Cryptogenic stroke is a diagnosis of exclusion. These are strokes that occur in people who are usually less than 55 years old, without an identifiable cause. Our sensitivity to these events has been heightened because of the new definitions of a transient ischemic attack. Transient ischemic attack (TIA) is a clinical diagnosis of a neurologic deficit without MRI abnormalities: if there is an MRI abnormality, whether or not that person is symptomatic, it is now defined as a stroke. With these new definitions, and the sensitivity of MRI, we are seeing more cryptogenic strokes. It has been hypothesized that many cryptogenic strokes are caused by small emboli that travel from the legs to the right atrium; during straining (such as a Valsalva maneuver) these emboli can go across a PFO into the left atrium and then travel to the brain, producing a stroke. The problem is that these are very small emboli, approximately 1 to 3 mm, and we can't actually show these small emboli crossing from right to left. However, large emboli have been observed by echocardiography to be trapped in the PFO. So the diagnosis of cryptogenic stroke is a diagnosis of exclusion that is impossible to verify. What is the scope of the problem? Of the 700,000 strokes per year in the United States, 80% of them are ischemic, and 20% of those are defined as cryptogenic. The prevalence of PFO among this cryptogenic stroke population is about 40% to 50%; in the general population, it's only about 20%. Current estimates are that somewhere between 30,000 and 60,000 strokes per year in the U.S. are caused by paradoxical embolism through a PFO. There are some other fascinating associations: scuba divers with PFOs are more susceptible to decompression illness. Platypnea-orthodeoxia is a condition of desaturation that occurs when you're standing up but not when you're lying down; these patients are quite symptomatic, with arterial saturations in the low 80s. They also frequently have PFOs; if you close the PFO, the arterial desaturation is alleviated. Fat emboli during orthopedic surgery or air emboli during neurosurgery may also travel through the venous system. If you don't have a PFO, the fat or the air is trapped in the lungs and doesn't cause much of a problem unless it's massive; but if you have a PFO, then the embolus can go from right to left atrium up to the brain, with devastating neurologic consequences.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 02/2005; 32(3):362-5. · 0.65 Impact Factor
  • Article: The incremental prognostic value of percentage of heart rate reserve achieved over myocardial perfusion single-photon emission computed tomography in the prediction of cardiac death and all-cause mortality: superiority over 85% of maximal age-predicted heart rate.
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    ABSTRACT: We sought to determine whether chronotropic incompetence (CI) adds incremental value in predicting cardiac death (CD) and all-cause mortality and to determine which marker of CI is superior. Chronotropic incompetence, defined by either a low percent heart rate (HR) reserve achieved or failure to achieve 85% maximal age-predicted heart rate (MA-PHR), is a predictor of mortality. These variables have not been examined together in a comprehensive myocardial perfusion single-photon emission computed tomographic (SPECT), or MPS, model. A total of 10,021 patients who underwent exercise MPS, evaluated by a summed stress score (SSS), were followed up for 719 +/- 252 days. Percent HR reserve = (peak HR - rest HR)/(220 - age - rest HR) x 100, with <80% considered abnormal. A total of 2,956 patients (29.5%) had low %HR reserve; 1,331 (13.3%) achieved <85% MA-PHR; and 1,296 (13.0%) had both. There were 234 deaths (93 CDs). On multivariate analysis, the SSS, %HR reserve, and inability to achieve 85% MA-PHR were predictors of all-cause mortality and CD (all p < 0.01). Myocardial perfusion SPECT was the most powerful predictor of CD (chi-square = 50). When the %HR reserve and ability to achieve 85% MA-PHR were considered, only the former remained a predictor of CD (p = 0.006 vs. p = 0.59). In a comprehensive MPS model, CI was an important predictor of CD and all-cause mortality. Percent HR reserve was superior to the ability to achieve 85% MA-PHR in predicting CD; MPS was superior to both. Combined with previous studies, the findings suggest that %HR reserve should become the standard for assessing the adequacy of HR response during exercise testing, and that it should be routinely incorporated in risk stratification algorithms.
    Journal of the American College of Cardiology 08/2004; 44(2):423-30. · 14.16 Impact Factor
  • Article: A prospective, nonrandomized, open-labeled pilot study investigating the use of magnesium in patients undergoing nonacute percutaneous coronary intervention with stent implantation.
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    ABSTRACT: Magnesium has recently been shown to inhibit acute stent thrombosis in animal models. This study tested the feasibility of magnesium administration in patients undergoing nonacute percutaneous coronary intervention with stent implantation. Twenty-one patients undergoing nonemergent percutaneous coronary intervention were enrolled and received intravenous magnesium sulfate (2-g bolus over 20 minutes prepercutaneous coronary intervention, followed by 14 g over 12 hours infusion). Endpoints: safety outcomes--hypotension, bradycardia, bleeding complications and heart block within first 24 hours; angiographic outcomes--acute thrombotic occlusion and need for platelet glycoprotein IIb/IIIa inhibitor bailout; and clinical outcomes--death, myocardial infarction, recurrent ischemia, and need for urgent revascularization at 48 hours and 30 days. No significant effects on heart rate or blood pressure, major bleeding complication, or new electrocardiographic changes were observed. Angiographic thrombus was visualized in two cases, and coronary artery dissection in one case poststent deployment. None of these cases required the use of glycoprotein inhibitors for bailout. Death, myocardial infarction, recurrent ischemia, and need for urgent revascularization were not observed. The serum magnesium level increased from 2.1 +/- 0.3 mg/dL at baseline to 3.5 +/- 0.8 mg/dL at the end of the infusion (P <.0001). Platelet activation was significantly inhibited at the end of the magnesium sulfate infusion. Intravenous magnesium sulfate has been demonstrated as a feasible and safe agent in patients undergoing nonacute percutaneous coronary intervention with stent implantation. A randomized clinical trial comparing magnesium with glycoprotein inhibitors during percutaneous coronary intervention is warranted.
    Journal of Cardiovascular Pharmacology and Therapeutics 10/2003; 8(3):193-200. · 1.75 Impact Factor
  • Article: Intramural delivery of recombinant apolipoprotein A-IMilano/phospholipid complex (ETC-216) inhibits in-stent stenosis in porcine coronary arteries.
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    ABSTRACT: We have previously demonstrated vasculoprotective effects after repeated intravenous administration of recombinant apolipoprotein A-IMilano (apoA-Im)/phospholipid complex. In this study, we sought to determine the effects of local recombinant apoA-Im/1-palmitoyl,2-oleoyl phosphatidylcholine complex (ETC-216) delivered intramurally via the Infiltrator catheter on luminal narrowing in a porcine coronary artery stent overstretch injury model. In twelve domestic swine ( approximately 25 kg), two arteries each were infiltrated with 0.4 mL ETC-216 (14 mg/mL) or vehicle control immediately before deployment of GFX stents (stent:artery ratio=1.3:1). Animals were euthanized at day 28, and evaluation by QCA revealed a significant improvement in mean lumen loss index with ETC-216 treatment (21+/-22% versus 43+/-13% lumen loss; P=0.01). Histomorphometric analysis showed that ETC-216 treatment significantly reduced the intimal area (6.7+/-1.5 versus 5.2+/-1.4 mm2, -22%; P=0.02) and the stenosis index (0.76+/-0.15 versus 0.59+/-0.15; P=0.01), and increased the lumen area (2.1+/-1.4 versus 3.7+/-1.8 mm2, +76%; P=0.02). Regression analysis showed significant differences in lumen area (P=0.004), neointimal area (P=0.003), stenosis index (P=0.001), and neointimal thickness (P=0.003) adjusted for injury score in favor of ETC-216. A single intramural administration of ETC-216 significantly inhibited injury-induced luminal narrowing in the porcine stent overstretch model through reduction of intimal hyperplasia. These data show that local intracoronary delivery of ETC-216 may be useful to prevent restenosis after coronary stenting.
    Circulation 06/2003; 107(20):2551-4. · 14.74 Impact Factor
  • Article: Effects of GP IIb/IIIa receptor inhibitor tirofiban (aggrastat) in ex vivo canine arteriovenous shunt model of stent thrombosis.
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    ABSTRACT: The authors investigated the effects of the platelet glycoprotein IIb/IIIa platelet inhibitor, tirofiban, on stent thrombosis in an ex vivo canine arteriovenous shunt model of high-shear blood flow. Control nitinol stents (n = 64) were expanded to 2 mm in diameter in a tubular perfusion chamber interposed in the shunt and exposed to flowing arterial blood at a shear rate of 2100/s for 20 min (n = 385 perfusion runs). Seven animals were treated with intravenous tirofiban (0.3, 3.0, and 30.0 microg x kg-1x min-1) with or without heparin (50 U/kg). Effects on thrombus weight, platelet aggregation, platelet P-selectin expression, bleeding time, D-dimer levels, and activated clotting time were quantified. Dethrombotic and antithrombotic effects were examined in stents with and without preformed thrombus, respectively. Tirofiban alone produced a dose-dependent reduction in preformed stent thrombus weight with 21% +/- 20% and 36% +/- 15% inhibition at 3- and 30-microg x kg-1x min-1 doses, respectively (P < 0.01). De novo stent thrombus formation was inhibited by 80% at 0.3 and >95% at 3- and 30-microg x kg-1x min-1 doses, respectively (all P < 0.001). Treatment with heparin and tirofiban produced no incremental inhibitory effect on stent thrombosis compared with tirofiban alone, except for the antithrombotic effect observed with the 0.3 microg x kg-1x min-1 dose. The inhibitory effects of tirofiban were associated with >95% suppression of platelet aggregation at 0.3 microg x kg-1x min-1 and complete inhibition at higher doses. Bleeding time was prolonged from 3.5 +/- 1.0 to 13 +/- 6 min at the 0.3 microg x kg-1x min-1 dose and >30 min at higher doses, but activated clotting time and circulating platelet P-selectin expression remained unchanged with tirofiban. A modest but significant platelet deaggregation effect and an increase in plasma D-dimer levels were observed with tirofiban at the 30-microg x kg-1x min-1 dose. Thus, tirofiban produced a dose-dependent dethrombotic effect on stent thrombosis and inhibited acute de novo stent thrombosis under high-shear flow conditions.
    Journal of Cardiovascular Pharmacology 04/2003; 41(4):615-24. · 2.29 Impact Factor