George Schroth

Intracoronary adenosine administered during percutaneous intervention in acute myocardial infarction and reduction in the incidence of 'no reflow' phenomenon

Percutaneous intervention in acute myocardial infarction has been associated with a high incidence of “no reflow,” ranging from 11% to 30%, with an increased risk of complications. The role of intracoronary adenosine for the prevention of this phenomenon has not been evaluated fully. We studied the procedural outcomes of 79 patients who underwent percutaneous intervention in the context of acute myocardial infarction. Twenty‐eight patients received no intracoronary adenosine, and 51 received intracoronary adenosine boluses (24–48 μg before and after each balloon inflation). Eight patients who were not given adenosine experienced no reflow (28.6%) and higher rates of in‐hospital death, while only three of 51 patients (5.9%; P =0.014) in the adenosine group experienced no reflow. No untoward complications were noted during adenosine infusion. Intracoronary adenosine bolus administration during percutaneous intervention in the context of acute myocardial infarction is easy and safe and may significantly lessen the incidence of no reflow, which may improve the outcome of this procedure. Cathet. Cardiovasc. Intervent. 51:27–31, 2000.

Infrapopliteal transcatheter interventions for limb salvage in diabetic patients: Importance of aggressive interventional approach and role of transcutaneous oximetry

OBJECTIVES This study sought to determine whether infrapopliteal transcatheter interventions can salvage ischemic limbs in diabetic patients referred for below the knee amputation at our institution. BACKGROUND The value of transcatheter interventions in diabetic crural arteries is controversial. Tissue oxygen partial pressure (TCO2) levels < 40 mm Hg predict poor wound healing. METHODS Percutaneous interventions were performed in 29 consecutive diabetic patients in need of limb salvage. Technical success was defined as < 20% residual vessel stenosis. Clinical success was defined as the avoidance of amputation and achievement of wound healing. At hospital discharge, patients were treated with Coumadin and aspirin. Ankle-brachial index (ABI) and TCO2 measurements were obtained before and after the intervention. RESULTS After 12-month follow-up, six patients had presistent wounds, whereas 23 experienced wound healing. Forty of the 50 infrapopliteal arteries successfully dilated were occluded, with a mean (+/-SD) lesion length of 18.0 +/- 3.5 cm. After the procedure, TCO2 improved from 27.82 +/- 9.97 mm Hg (95% confidence interval [CI] 23.95 to 31.69) to 54.5 +/- 14.73 mm Hg (95% CI 48.79 to 60.21, p < 0.0001), whereas the ABI did not (p > 0.2). TCO2 predicted procedural and clinical success (p < 0.0182). CONCLUSIONS Infrapopliteal transcatheter interventions in diabetic patients may salvage the majority of limbs doomed to amputation. Although TCO2 measurements are valuable in predicting wound healing and success after interventions, ABI measurements are not.

Adenosine use during aortocoronary vein graft interventions reverses but does not prevent the slow-no reflow phenomenon.

Slow or no reflow (SNR) complicates 10–15% of cases of percutaneous intervention (PI) in saphenous vein bypass graft (SVG). To date there have been limited options for the prevention and treatment of this common and potentially serious complication. We evaluated the procedural outcome of 143 consecutive SVG interventions. We compared patients who received pre‐intervention intra‐graft adenosine boluses with those who did not. In addition we examined the efficacy of adenosine boluses to reverse slow‐no reflow events. Angiograms were reviewed and flow graded (TIMI grade) by film readers blinded to the use of any intraprocedural drug or clinical history. Seventy patients received intragraft adenosine boluses before percutaneous intervention (APPI), 73 received no preintervention adenosine (NoAPPI). There were no significant angiographic differences between the two groups at baseline. A total of 20 patients experienced SNR. The incidence of SNR was similar in the two groups (APPI = 14.2% vs. NoAPPI = 13.6%, P = 0.9). SNR was treated with repeated, rapid boluses (24 μg each) of intra‐graft adenosine. Reversal of SNR was observed in 10 of 11 patients (91%) who received high doses of adenosine (≥5 boluses, mean 7.7 ± 2.6) and in 3 of 9 (33%) of those who received low doses (<5 boluses, mean 1.5 ± 1.2). Final TIMI flow was significantly better in the high dose than in the low dose group (final TIMI 2.7 ± 0.6 vs. 2 ± 0.8, P = 0.04). No significant untoward complications were observed during adenosine infusion. These findings suggest that SNR after PI in SVG is not prevented by pre‐intervention adenosine, but it can be safely and effectively reversed by delivery of multiple, rapid and repeated boluses of 24 μg of intra‐graft adenosine. Cathet. Cardiovasc. Intervent. 51:394–399, 2000.

Comparison of angioscopy, intravascular ultrasound imaging and quantitative coronary angiography in predicting clinical outcome after coronary intervention in high risk patients

OBJECTIVES The purpose of this study was to identify qualitative or quantitative variables present on angioscopy, intravascular ultrasound imaging or quantitative coronary arteriography that were associated with adverse clinical outcome after coronary intervention in high risk patients. BACKGROUND Patients with acute coronary syndromes and complex lesion morphology on angiography are at increased risk for acute complications after coronary angioplasty. Newer devices that primarily remove atheroma have not improved outcome over that of balloon angioplasty. Intravascular imaging can accurately identify intraluminal and intramural histopathologic features not adequately visualized during coronary arteriography and may provide mechanistic insight into the pathogenesis of abrupt closure and restenosis. METHODS Sixty high risk patients with unstable coronary syndromes and complex lesions on angiography underwent angioscopy (n = 40) and intravascular ultrasound imaging (n = 46) during interventional procedures. In 26 patients, both angioscopy and intravascular ultrasound were performed in the same lesion. All patients underwent off-line quantitative coronary arteriography. Coronary interventions included balloon (n = 21) and excimer laser (n = 4) angioplasty, directional (n = 19) and rotational (n = 6) atherectomy and stent implantation (n = 11). Patients were followed up for 1 year for objective evidence for recurrent ischemia. RESULTS Patients whose clinical presentation included rest angina or acute myocardial infarction or who received thrombolytic therapy within 24 h of procedure were significantly more likely to experience recurrent ischemia after intervention. Plaque rupture or thrombus on preprocedure angioscopy or angioscopic thrombus after intervention were also significantly associated with adverse outcome. Qualitative or quantitative variables on angiography, intravascular ultrasound or off-line quantitative arteriography were not associated with recurrent ischemia on univariate analysis. Multivariate predictors of recurrent ischemia were plaque rupture on preprocedure angioscopy (p < 0.05, odds ratio [OR] 10.15) and angioscopic thrombus after intervention (p < 0.05, OR 7.26). CONCLUSIONS Angioscopic plaque rupture and thrombus were independently associated with adverse outcome in patients with complex lesions after interventional procedures. These features were not identified by either angiography or intravascular ultrasound.

Outcome of access site in patients treated with platelet glycoprotein IIb/IIIa inhibitors in the era of closure devices

The most consistent procedural predictor of vascular access site complications thus far has been the intensity and duration of anticoagulant therapy during and after percutaneous coronary interventions (PCI). Several devices have been developed to aid in the closure of the femoral arteriotomy. This report describes the clinical outcome of unsuccessful deployment of femoral closure devices in a cohort of 285 consecutive patients who underwent PCI and were treated with platelet glycoprotein (GP) IIb/IIIa inhibitors. Manual femoral artery compression was used in 123 patients, Perclose in 123 patients, and AngioSeal in 39 patients. Successful homeostasis was achieved in 98.4% of patients who received manual compression, in 91.9% of the Perclose‐sealed arteriotomy, and in 84.6% of patients who received the AngioSeal closure device (P = 0.004). The incidence of vascular complications after successful deployment was 9%. Patients not achieving hemostasis with closure device or 1° manual compression developed complications in the majority of cases (> 80%; P < 0.05). By multivariate analysis (with adjustment for baseline differences), the use of AngioSeal closure device was found to be an independent risk factors leading to primary deployment failure and all access site complications (OR 2.97; 95% CI 1.5–6.0; P = 0.006). In summary, failed hemostasis by artery closure devices in patients undergoing PCI who are treated with GP IIb/IIIa inhibitors is associated with significant vascular complications. AngioSeal may be associated with a higher failure rate, while manual compression and Perclose seem to be more effective with a lower complication rate. Cathet Cardiovasc Intervent 2003;58:1–5.

Effects of clopidogrel pretreatment before percutaneous coronary intervention in patients treated with glycoprotein IIb/IIIa inhibitors (abciximab or tirofiban)

T clinical efficacy and safety of clopidogrel pretreatment in addition to glycoprotein (GP) IIb/IIIa antagonists during percutaneous coronary intervention (PCI) is unknown. This study compares the in-hospital clinical outcome of patients who received clopidogrel pretreatment before PCI with that in patients who did not receive it as adjunctive antiplatelet therapy to GP IIb/IIIa antagonists. • • • Data were collected from the Memorial Hermann Heart Center Interventional Cardiology database. We examined a consecutive series of 299 patients undergoing PCI. All patients received GP IIb/IIIa inhibitor therapy in the form of abciximab or tirofiban. Use and type of GP IIb/IIIb antagonists was at the discretion of the operator. Abciximab was given as a bolus dose of 0.25 mg/kg body weight followed by continuous infusion of 10 g/min for 12 hours. Tirofiban was given as a loading dose of 0.4 g/kg/min for 30 minutes followed by a maintenance dose of 0.1 g/kg/min for 12 to 24 hours after the procedure. All patients were taking aspirin and received a heparin bolus to achieve an activated clotting time between 250 and 300 seconds. Patients presenting to the catheterization laboratory with a developing myocardial infarction (MI) for a primary or rescue angioplasty were excluded. Patients were divided into 2 groups: those who received clopidogrel pretreatment before PCI (starting within 5 days before PCI or a loading dose of 300 mg the morning of the day of the procedure at the discretion of the primary operator, group I), and those who received aspirin alone (group II) with clopidogrel (300 mg loading dose and 75 mg/day for 1 month) given after stent deployment. Therapy with clopidogrel (75 mg/day) was continued for 1 month in both groups if the stent was deployed during the procedure. Coronary angioplasty and intracoronary stent implantation were performed using standard percutaneous techniques. Balloon size was selected to match the reference vessel diameter obtained from on-line angiographic analysis (1.1:1 balloon/artery ratio). Different types of stents were used (excluding open coil type). After stent implantation, high-pressure balloon dilatation was performed for angiographic optimization. Intravascular ultrasonography–guided coronary stenting was not performed in most patients. Each operator relied on his own judgment or on other objective measurements, such as online quantitative coronary angiography, to assess PCI results. On completion of the procedure, patients were moved to a monitored unit and the arterial sheath was removed. Successful PCI was defined as final residual stenosis within the treated lesion of 20%, with achievement of Thrombolysis In Myocardial Infarction grade 3 flow, without in-lab occurrence of death, MI, or a complication requiring immediate coronary revascularization. A major adverse cardiac event was defined as any 1 of the following: (1) Q-wave or non–Q-wave MI, (2) need for urgent repeat target vessel revascularization, or (3) cardiovascular death that occurred during the period of hospitalization after the index coronary procedure. Postprocedural MI was defined as the occurrence of typical ischemic chest pain of 30 minutes duration with a creatine kinase elevation of 3 times the upper limit of normal with an associated increase in the MB fraction. There was no routine protocol for acquisition of postprocedure creatine kinase. All postprocedural cardiac enzymes were obtained for suspected recurrent myocardial ischemia, manifested by recurrent postprocedural chest pain, hemodynamic instability, or new electrocardiographic changes of ischemia. Urgent target vessel revascularization was defined as a repeat PCI or coronary artery bypass grafting of the index artery due to presumed recurrent ischemia manifested by recurrent angina, arrhythmias, or hemodynamic compromise. Adverse effects of therapy were recorded and compared between the 2 groups. These consist of major bleeding and thrombocytopenia. Major bleeding was defined as bleeding requiring transfusion of blood products or precipitating hemodynamic compromise. Intracerebral hemorrhage of any extent was considered a major adverse effect of therapy. Thrombocytopenia was defined as platelet count 100,000/mm. Chi-square and Fischer exact tests were used for analysis of categorical variables when appropriate, and Student t testing was used for analysis of continuous variables. Multivariate logistic regression analysis was performed to determine significance of variables related to an in-hospital major adverse cardiac From the Cardiology Division, University of Texas Medical School and Hermann Heart Center, Memorial Hermann Hospital, Houston, Texas. Dr. Rosales’ address is: Division of Cardiology, University of Texas Health Science Center-Houston, PO Box 20708, Houston, Texas 77225-0708. Manuscript received March 29, 2001; revised manuscript received and accepted May 30, 2001.

Estrogen replacement therapy and outcome of coronary balloon angioplasty in postmenopausal women

Estrogen replacement therapy (ERT) in women after menopause is associated with prevention of clinical coronary artery disease. However, few studies have investigated possible benefits from ERT in postmenopausal women undergoing treatment for established coronary disease. We therefore retrospectively reviewed the clinical outcomes of 428 postmenopausal women undergoing percutaneous transluminal coronary balloon angioplasty (PTCA) to test the hypothesis that ERT has a beneficial effect in this setting. The women were divided into 2 groups based on ERT status at the time of the procedure. Estrogen users were younger (60 +/- 10 vs 68 +/- 9 years, p <0.001), more commonly had family histories of coronary heart disease (54% vs 41%, p = 0.04), had less incidence of hypertension (63% vs 76%, p = 0.02), and had slightly fewer diseased vessels per patient (1.3 +/- 0.5 vs 1.5 +/- 0.7, p = 0.03) compared with nonusers. No in-hospital deaths occurred in estrogen users compared with 5% hospital mortality in nonusers (p = 0.01). The combined outcome of death or myocardial infarction (MI) also was lower in estrogen users (4% vs 12%, p = 0.04). Of 348 women discharged after successful PTCA, 336 (97%) were able to be contacted at an average follow-up interval of 22 +/- 17 months (range 5 to 82). Estrogen users had superior event-free survival both for death as well as for death or nonfatal MI. Repeat revascularizations were similar in both groups (32% vs 24%, p = 0.15). In a Cox proportional-hazards model, nonusers had 4 times the likelihood of death after angioplasty compared with estrogen users (OR = 4.025, 95% CI = 1.3 to 13.4, p = 0.02). We conclude that estrogen replacement may offer protection against clinical coronary events in postmenopausal women who already have established coronary disease and are undergoing balloon angioplasty. The benefit was independent of age, smoking, presence of diabetes mellitus, or the number of diseased coronary vessels. However, it did not include a reduction in repeat revascularization procedures, suggesting no reduction in restenosis.

Episodic Tachycardia in a 12-Year-Old Girl

A 12-year-old girl first presented to her family physician in January 1991 with an episode of tachycardia and dyspnea. Her mother described the patient’s appearance during the event as “like a statue,” extremely pale, gray, and lethargic. An ECG at that time showed sinus tachycardia with a rate of 143 bpm and T-wave inversion in lead III (Fig 1⇓). Oxygen was administered in the office, and a trial of propranolol 10 mg/d was begun. Figure 1. ECG obtained in office of family physician as symptoms were resolving. The girl’s symptoms had first occurred 6 months earlier and were of variable duration and severity. Tachycardia would persist for several hours and be associated with dyspnea and pallor. During the episode, she would develop generalized myalgia, weakness, and fatigue and then sleep for 2 to 7 hours. There was no associated chest pain, dizziness, or presyncope. Episodes occurred one to three times per week, in the afternoon, and were unrelated to activity. She had decreased exercise tolerance compared with her peers. She was referred to a pediatric cardiologist for further evaluation. A Holter recording was normal. Her cardiac examination was normal; however, an echocardiogram reportedly showed discontinuity of the atrial septum, with left-to-right flow across the interatrial septum by pulsed Doppler and color flow Doppler. The diagnosis of secundum atrial septal defect was made and a cardiac catheterization recommended, but the family declined. Propranolol was discontinued, in part because of a history of asthma. Verapamil was started but was soon discontinued because of dizziness. The family then sought a second opinion. The patient was the product of a 31-week gestation, with delivery by emergency cesarean section for preterm labor with fetal distress. Birth weight was 4 lb 1 oz. She remained hospitalized for 1 month as a neonate, requiring ventilation and oxygen administration. …

Eosinophilic pericarditis and myocarditis

A 58-year-old African-American woman with long-standing asthma presented with a 1 month history of severe dyspnea on exertion, orthopnea, and weight loss. One week before hospitalization, she could only sleep sitting in a chair. She was found to have 50% eosinophils on peripheral blood smear …

Thrombus and unstable angina

Three clinical cases have been selected to focus on the role of thrombosis in unstable and refractory angina. The histories are abbreviated for simplicity. For example, it can be assumed that non-coronary causes of chest discomfort have been excluded, and that exacerbating factors such as anaemia, hyperthyroidism, hypoxia, arrhythmia, valve disease, obvious coagulopathy, and emotional stress have also been excluded by history, examination, and appropriate testing. These patients all underwent coronary angiography for severe symptoms associated with marked electrocardiographic or haemodynamic changes (and therefore did not undergo radionuclide stress testing) or for symptoms refractory to a medical regimen of rest, reassurance, oxygen, nitrates, cardioselective beta blockers, aspirin 325 mg once or twice daily, heparin 1000 U/h, and sometimes, calcium antagonists and sedatives.