Sanjiv Sharma

Delayed profound thrombocytopenia presenting 7 days after use of abciximab (ReoPro)

A case of a 65-year-old woman presenting with delayed profound thrombocytopenia 7 days after the use of abciximab (ReoPro) in the setting of percutaneous coronary intervention is described. The patient had normal platelet counts for the first 24 hours after the use of abciximab (ReoPro). She presented with petechiae and profound thrombocytopenia 1 week later. The patient was treated successfully with a platelet transfusion and recovered uneventfully. Profound thrombocytopenia occurs acutely within the first few hours after abciximab (ReoPro) use, so this case was unique in that the profound thrombocytopenia presented 1 week after use of abciximab (ReoPro).

Oral Midodrine Is Effective for the Treatment of Hypotension Associated With Carotid Artery Stenting

Hypotension is commonly encountered during carotid artery stenting (CAS), mediated by vagal stimulation and suppression of sympathetic outflow. Some patients require treatment with intravenous vasopressors (dopamine, nor-epinephrine, or phenylephrine). The authors describe the successful use of the oral agent midodrine as an alternative to intravenous vasopressors in the treatment of hypotension related to CAS. Of 55 patients who underwent elective CAS, 19 (35%) experienced significant hypotension, and 15 (27%) required vasopressor therapy. Eleven patients received intravenous dopamine infusion in an intensive care setting, whereas 4 received oral midodrine in a regular telemetry unit. All patients eventually recovered and were discharged without any residual cardiovascular or neurological complications. No major side effects were noted with the use of both dopamine and midodrine. Cost of hospitalization was significantly higher in the dopamine group because of the need for ICU admission.

Intracoronary Administration of Abciximab During Percutaneous Coronary Interventions: Should This Be the Routine and Preferred Approach?

The authors have had experience with administering abciximab as an intracoronary bolus in 96 high-risk patients undergoing percutaneous coronary interventions, specifically in situations in which there was anticipation of a high embolic load from thrombus/plaque burden at the site of the culprit lesion, saphenous vein graft culprit lesion, threatened abrupt closure, developing slow-flow, or no-reflow phenomena with distal embolization. Our uncontrolled data basically substantiate the safety of intracoronary administration of abciximab. The data summarizing the potential superiority of this method of administration of the drug and the likely mechanisms of this effect are summarized. These incite a need for reevaluation of the method of administration of the drug, especially in high-risk percutaneous coronary interventions cases

Successful Treatment of Hypotension Associated With Stunned Myocardium with Oral Midodrine Therapy

Myocardial stunning, a reversible decrease in the contractile function of the myocardium after an ischemic insult, often leads to hypotension that requires therapy with intravenous inotropes. We used the oral agent midodrine to treat hypotension that complicated myocardial stunning after successful revascularization with percutaneous coronary intervention in the setting of myocardial infarction and ischemia. Oral midodrine may offer a useful substitute to intravenous inotropic therapy and can shorten the duration of intensive care unit and hospital stay in this setting.

Bivalirudin (Angiomax) Use during Intracoronary Brachytherapy May Predispose to Acute Closure

We describe two cases of intracoronary vascular brachytherapy where bivalirudin (Angiomax), employed as an anticoagulant, led to abrupt vessel closure or threatened abrupt closure. Use of bivalirudin (Angiomax) during intracoronary brachytherapy may predispose to the formation of intracoronary thrombus, related to the reversible binding kinetics of the bivalirudin to thrombin, and resulting in recovery of thrombin functional activity during periods of prolonged stasis that occur during intracoronary brachytherapy. Intracoronary abciximab administration may be a useful strategy in resolving the acute closure, since abciximab administered early during the formation of thrombus has been shown to facilitate clot lysis.

Vertebral artery stenting utilizing distal embolic protection with filter wire and a drug‐eluting Taxus stent

Percutaneous intervention of the vertebral artery stenosis is associated with the risk of distal embolization and restenosis, which can manifest with stroke. We describe a case of vertebral artery percutaneous intervention utilizing the embolic protection FilterWire and a drug‐eluting Taxus stent, to overcome these issues of distal embolization and restenosis respectively.

Intra-Graft Abciximab and Verapamil Combined with Direct Stenting is a Safe and Effective Strategy to Prevent Slow-flow and No-Reflow Phenomenon in Saphenous Vein Graft Lesions not Associated with Thrombus

UNLABELLED Slow flow and no-reflow phenomenon (SF-NR) in saphenous vein grafts (SVG) stenting is related to the occurrence of distal plaque embolization, platelet activation and microvascular vasospasm. Our article discusses few of the patents related to strategies for preventing slow-flow/no-reflow phenomenon in SVG percutaneous coronary intervention (SVG PCI). METHODS Data from 163 consecutive patients who underwent PCI of SVG lesions without visible macro-thrombus without use of distal embolic protection device over a 10-year period were reviewed. Patients in the novel strategy group received prophylactic intra-graft administration of abciximab and verapamil followed by direct stenting (n=91). The control group (n=72) comprised of patients who had undergone conventional PCI technique before the routine availability of distal embolic protection devices, with balloon pre-dilatation of the target lesion followed by stent deployment and optional use of intragraft verapamil or intravenous abciximab. Patients with visible macro-thrombus in the vein graft were excluded from the study, since these patients underwent PCI with use of the distal embolic protection (filter). RESULTS SF-NR (TIMI 0-1 flow) occurred more frequently in the control group compared to the novel strategy group (18% vs. 1%, P=0.0001). One patient in the control group died after developing persistent SF-NR and acute MI post-PCI. No death was reported in the novel strategy group. In the control group, 13% patients developed cardiac enzyme elevation 3 times more than normal after the PCI as compared to 1% in the novel strategy group (P < 0.05). CONCLUSIONS In recent years several distal embolic protection devices have been granted patents for minimizing the chance of slow-flow/no-reflow phenomenon. In carefully selected subgroup of SVG lesions without visible macrothrombus, a strategy of prophylactic intra-graft administration of abciximab and verapamil, combined with direct stenting of the graft lesion without pre-dilatation, can be safely accomplished without any significant risk of slow-flow/no-reflow phenomenon. We propose a patent to this 3-step strategy of percutaneous coronary intervention of SVG lesions not associated with thrombus.

Use of platelet transfusion to facilitate surgery in patients on clopidogrel and aspirin therapy after drug‐eluting stent percutaneous coronary intervention

In reference to the study by Gandhi et al. [1], we would like to report a pilot trial in which we tested a strategy of prophylactic platelet transfusion immediately before surgery or procedures that were deemed by the surgeon as otherwise unacceptable to undertake without interrupting clopidogrel and aspirin, in a group of patients who had undergone drug-eluting stent (DES) percutaneous coronary intervention (PCI) within the last 12 months [2]. The dose of clopidogrel and aspirin was with-held on the day before surgery. Patients received 10–20 units of platelet transfusion immediately before surgery. Adenosine diphosphate (ADP) aggregation testing was performed preoperatively in certain high-risk surgeries to ensure adequate platelet function had been restored (ADP aggregation >80%) before the surgical procedure, especially if the surgery involved high bleeding risk. Clopidogrel (75 mg once a day) and aspirin (325 mg once a day) therapy was resumed postoperative day zero or day one. Thus, all the patients had an interruption of clopidogrel and aspirin for less than 2 days. Patients were evaluated for death, myocardial infarction, stent thrombosis or revascularization, postoperative bleeding, and requirement for blood transfusion. A total of 37 patients underwent elective or urgent surgery using this strategy. These included 8 vascular, 15 abdominal, 10 orthopaedic, and 4 prostate procedures. The postoperative bleeding and blood transfusion requirements were within the standard as reported by the surgeon. There were no major adverse cardiac events reported in the group. We concluded that surgery, including elective surgery, could be safely accomplished within 12 months after DES PCI, without long term interruption of clopidogrel and aspirin therapy, if platelet transfusion is used on the day of the surgery to normalize platelet function for the surgical procedure. This strategy obviates long term (5–7 days) interruption of clopidogrel therapy that is usually requested by surgeons in undertaking surgeries involving bleeding risk while on clopidogrel therapy.

A Review of Intracoronary Abciximab in Percutaneous Coronary Interventions- where are we now and where do we go from here?

The rationale for intracoronary administration of abciximab is discussed. The data on use of intracoronary abciximab in percutaneous coronary interventions in acute coronary syndromes and STEMI are reviewed. Evaluation of the niche where intracoronary administration of abciximab may be useful and future research into the subject and relevant patents are discussed.

Extensive fatal intracoronary thrombosis during percutaneous coronary intervention with bivalirudin.

The authors describe 2 cases of extensive intracoronary thrombus formation leading to acute closure of the left main where bivalirudin (Angiomax) was used as the anticoagulant during percutaneous coronary intervention leading to mortality. Both cases had similarity in the cascade of complications of coronary dissection leading to slow flow and prolonged procedure time with compromise of antegrade flow in the coronary artery and a final catastrophic development of extensive intracoronary thrombosis extending into the left main and nonintervened vessel (left anterior descending or circumflex) followed by ventricular fibrillation and death. Bivalirudin has reversible anticoagulant pharmacodynamics because the bivalirudin molecule is cleaved by the thrombin molecule. In situations when the antegrade flow is compromised, delivery of fresh circulating bivalirudin to replenish the catalysis of bivalirudin by thrombin is diminished, allowing thrombin activity to regenerate, thereby creating a prothrombotic milieu in these coronary segments. This can lead to extensive intracoronary thrombus formation in situations of slow flow precipitated by coronary dissection and prolonged dwell time with intracoronary hardware (wires, balloons, and stents). Interventionalists should be aware of the potential risk of this fatal complication and should be proactive in recognizing the scenarios where this is likely to occur. In such anticipated circumstances, the interventionalist may judiciously switch the anticoagulant to heparin and/or use additional glycoprotein IIb/IIIa inhibitor because freshly formed intracoronary thrombus is susceptible to lysis by glycoprotein IIb/IIIa inhibitors.