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Biomedical subjects

Gary L Schaer

Publications and source records attributed to Gary L Schaer.

At least 19 recordsLinked to original sources
PubMed2005

Long-term (2-year) clinical events following transthoracic intramyocardial gene transfer of VEGF-2 in no-option patients.

BACKGROUND: The short-term clinical impact of intramyocardial gene transfer (GT) of the angiogenic protein vascular endothelial growth factor-2 (VEGF-2) has been previously reported to significantly reduce Canadian Cardiovascular Society (CCS) angina class and to prolong exercise treadmill test (ETT) time. We describe the safety and long-term events (>1 year) in consecutive, nonrandomized, patients who received intramyocardial VEGF-2. METHODS: Thirty patients with intractable CCS class III or IV angina and no options for revascularization underwent direct intramyocardial GT of VEGF-2 naked DNA via limited thoracotomy at total doses of 0.2, 0.8, or 2.0 mg. Patients were followed for clinical events after 1 year by hospital records, follow-up visits or telephone contact. Due to one perioperative death, 29 patients were followed. RESULTS: At a mean follow-up of 751 +/- 102.5 days (range 459-959) there were four deaths (13.8%), five myocardial infarctions (MIs) (17.2%), and seven revascularization procedures (24.1%). There were 15 hospitalizations in 12 patients. At the end of the follow-up period no patient (0%) had CCS class IV angina, 3 patients (11.5%) had class III angina, and 23 (88.5%) had class I to II angina. There were two new diagnoses of cancer. CONCLUSION: Transthoracic intramyocardial injection of VEGF-2 is associated with an improvement of symptoms of angina in the majority of patients beyond the first year of treatment. Major clinical events such as death, MI, and repeat revascularization are uncommon during the first year but more frequent after 1 year at a rate consistent with the severity of underlying disease in this population with advanced atherosclerosis. The majority of events were the result of progression of disease in areas of the heart remote from the site of GT. A large randomized trial is planned to determine the efficacy of intramyocardial VEGF-2 injections in inoperable patients.

Adult↗
PubMed2005

Myocardial infarction after taking zolmitriptan.

We report the case of a patient with mild non-obstructive coronary artery disease who sustained an inferior wall myocardial infarction shortly after taking zolmitriptan as abortive therapy for migraine headaches. A Medline search was performed to review all reported cases of myocardial infarction related to migraine therapy with zolmitriptan and related medications. Zolmitriptan may cause myocardial infarction (MI) even in the absence of significant coronary artery disease.

Aged↗
PubMed2004

Noncardiac applications of glycoprotein IIb/IIIa inhibitors.

Platelet activation and aggregation have become increasingly recognized as the primary processes involved in the cascade that leads to thrombus formation in atherosclerotic vascular disease. Glycoprotein IIb/IIIa receptor inhibitors (GPI) favorably impact thrombus formation and distal embolization by inhibiting the final common pathway of platelet aggregation. Glycoprotein IIb/IIIa inhibitors have been used effectively in a wide variety of clinical scenarios including unstable angina, non-ST segment elevation myocardial infarction, ST segment elevation myocardial infarction, and low and high risk percutaneous coronary interventions with and without intracoronary stenting, however there is limited data regarding the use of these potent antiplatelet agents in the setting of extracardiac vascular disease. This article will review the non-cardiac applications of glycoprotein IIb/IIIa inhibitors in the setting of acute ischemic stroke, carotid and vertebral angioplasty and stenting, acute critical limb ischemia, and percutaneous interventions in peripheral arterial occlusive disease.

Acute Disease↗
PubMed2003

Fenoldopam mesylate for the prevention of contrast-induced nephropathy: a randomized controlled trial.

CONTEXT: The development of contrast-induced nephropathy in patients undergoing invasive cardiac procedures is associated with a marked increase in cardiovascular morbidity and mortality. Fenoldopam mesylate, a specific agonist of the dopamine-1 receptor, preserves renal blood flow after iodinated contrast administration and has shown promise in ameliorating contrast nephropathy in previous observational and small randomized trials. OBJECTIVE: To examine the efficacy of fenoldopam mesylate in preventing contrast nephropathy after invasive cardiovascular procedures. DESIGN: Prospective, placebo-controlled, double-blind, multicenter randomized trial with serial serum creatinine levels measured at a central biochemistry laboratory (at baseline and 1, 24, 48, and 72 to 96 hours after study drug administration) and 30-day clinical follow-up. PATIENTS AND SETTING: Between March 2001 and July 2002, 315 patients with creatinine clearance less than 60 mL/min (1.00 mL/s) at 28 centers in the United States were randomized to receive fenoldopam mesylate (n = 157) or placebo (n = 158). INTERVENTIONS: Patients were hydrated and randomized to receive intravenous fenoldopam (0.05 microg/kg/min titrated to 0.10 microg/kg/min) vs matching placebo, starting 1 hour prior to angiography and continuing for 12 hours. MAIN OUTCOME MEASURE: Contrast-induced nephropathy, defined as an increase of 25% or more in serum creatinine level within 96 hours postprocedure. RESULTS: Mean (SD) patient age was 70 (11) years, and 49% had diabetes mellitus. Mean (SD) baseline creatinine clearance was 29.0 (10.0) mL/min (0.48 [0.16] mL/s) (range, 7.5-56.8 mL/min [0.12-0.94 mL/s]), and 157 (108) mL of contrast was administered during the procedures. The primary end point of contrast-induced nephropathy occurred in 33.6% of patients assigned to receive fenoldopam vs 30.1% assigned to receive placebo (relative risk, 1.11; 95% confidence interval, 0.79-1.57; P =.61). There were no significant differences in the 30-day rates of death (2.0% vs 3.8%, P =.50), dialysis (2.6% vs 1.9%, P =.72), or rehospitalization (17.6% vs 19.9%, P =.66) in fenoldopam vs placebo randomized patients, respectively. CONCLUSION: The selective dopamine-1 agonist fenoldopam mesylate does not prevent further renal function deterioration after contrast administration in patients with chronic renal insufficiency.

Adult↗
PubMed2003

One-year follow-up of direct myocardial gene transfer of vascular endothelial growth factor-2 using naked plasmid deoxyribonucleic acid by way of thoracotomy in no-option patients.

This phase I open label, dose-escalating study shows that gene transfer of vascular endothelial growth factor-2 naked deoxyribonucleic acid by direct myocardial injection by way of thoracotomy in patients with Canadian Cardiovascular Society class 3 or 4 angina is feasible and safe. The procedure is well tolerated, with few major adverse cardiac events at 1 year, and without complications directly related to gene expression. In this prospective, nonblinded study, the procedure is associated with clinical improvement; however, there was no angiographic evidence of angiogenesis and there is a great potential for a sham or placebo effect in the study patients. A randomized phase III trial is underway that will help determine the efficacy of vascular endothelial growth factor-2 gene transfer in "no-option" patients.

Adult↗
PubMed2003

Correlates of failure following treatment with Sr-90 beta irradiation for in-stent restenosis.

We sought to determine the correlates of failure following intracoronary radiation therapy (IRT) with Sr-90 using the Novoste Beta-Cath system for the treatment of in-stent restenosis (ISR) in a broad range of patients. IRT has been shown to be more efficacious compared to placebo for the treatment of ISR in large randomized trials. However, even in patients treated with IRT, major adverse cardiac events occur in approximately 20% of cases on follow-up. This trial sought to elucidate the correlates of failure following successful IRT for ISR. To determine the correlates of IRT failure, we retrospectively compared the demographics, lesion characteristics, and clinical outcomes of 102 consecutive patients with ISR treated with Sr-90 from September 1998 to July 2001. IRT failure was defined as death, myocardial infarction (MI), or target vessel revascularization (TVR) due to repeat ISR on follow-up. A comparison of the clinical and angiographic profile of IRT failures (n = 16) vs. IRT successes (n = 86) revealed that a history of smoking (75% vs. 40%; P = 0.012), current use of calcium channel blockers (84% vs. 45%; P = 0.013), ostial location of target lesion (44% vs. 16%; P = 0.020), and mean posttreatment minimal luminal diameter (MLD; 1.64 +/- 0.19 vs. 2.21 +/- 0.29 mm; P < 0.001), respectively, were correlated with failure using univariate analysis. After multivariate regression analysis, the correlates of failure that remained significant were treatment of an ostial lesion (OR = 31.2; 95% CI = 2.6-382.7; P = 0.007) and final posttreatment MLD (P < 0.001). Ostial location of target lesion and smaller posttreatment MLD are correlated with subsequent death, MI, and TVR following therapy with Sr-90 for ISR.

Aged↗
PubMed2002

Induction of mild systemic hypothermia with endovascular cooling during primary percutaneous coronary intervention for acute myocardial infarction.

OBJECTIVES: The purpose of this study was to evaluate the safety and feasibility of endovascular cooling during primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). BACKGROUND: In experimental models of AMI, mild systemic hypothermia has been shown to reduce metabolic demand and limit infarct size. METHODS: In a multi-center study, 42 patients with AMI (<6 h from symptom onset) were randomized to primary PCI with or without endovascular cooling (target core temperature 33 degrees C). Cooling was maintained for 3 h after reperfusion. Skin warming, oral buspirone, and intravenous meperidine were used to reduce the shivering threshold. The primary end point was major adverse cardiac events at 30 days. Infarct size at 30 days was measured using (99m)Tc-sestamibi SPECT imaging. RESULTS: Endovascular cooling was performed successfully in 20 patients (95%). All achieved a core temperature below 34 degrees C (mean target temperature 33.2 +/- 0.9 degrees C). The mean temperature at reperfusion was 34.7 +/- 0.9 degrees C. Cooling was well tolerated, with no hemodynamic instability or increase in arrhythmia. Nine patients experienced mild episodic shivering. Major adverse cardiac events occurred in 0% vs. 10% (p = NS) of treated versus control patients. The median infarct size was non-significantly smaller in patients who received cooling compared with the control group (2% vs. 8% of the left ventricle, p = 0.80). CONCLUSIONS: Endovascular cooling can be performed safely as an adjunct to primary PCI for AMI. Further clinical trials are required to determine whether induction of mild systemic hypothermia with endovascular cooling will limit infarct size in patients undergoing reperfusion therapy.

Adult↗
PubMed2002

The relationships of left ventricular ejection fraction, end-systolic volume index and infarct size to six-month mortality after hospital discharge following myocardial infarction treated by thrombolysis.

OBJECTIVES: We sought to relate left ventricular ejection fraction (EF), end-systolic volume index (ESVI) and infarct size (IS), as measured in a single randomized trial, to six-month mortality after myocardial infarction (MI) treated with thrombolysis. BACKGROUND: These three prognostic indicators have never been compared in the same study group. METHODS: Radionuclide angiographic and single-photon emission computed tomographic sestamibi measurements of IS were performed in 1,194 and 1,181 patients, respectively, of the 2,948 patients enrolled in the Collaborative Organization for RheothRx Evaluation (CORE) trial. Ejection fraction, ESVI and IS, as measured by central laboratories in these radionuclide substudies, were tested for their association with six-month mortality. RESULTS: Ejection fraction (n = 1,137; p < 0.0001), ESVI (n = 945; p = 0.055) and IS (n = 1,164; p = 0.03) were all associated with six-month mortality. Each of these measurements was significantly correlated with the other two, regardless of MI location. In an "overlap" group of 753 patients (25.5% of the population; 13 deaths) in whom all three measurements were available, EF (p = 0.001) was a stronger predictor than ESVI (p = 0.005) or IS (p = 0.01). Neither of the other two measurements added independent prognostic information. The highest risk subgroup (EF < 30%) had an 11% six-month mortality, but comprised only 95 patients (8.3%). CONCLUSIONS: Ejection fraction, ESVI and IS measurements performed one to two weeks after MI can each predict six-month mortality. Ejection fraction was superior to the other two measurements. However, this study had limited power to detect independent significance of ESVI or IS.

Female↗
PubMedDate not supplied

Intracoronary beta brachytherapy as a treatment option for high-risk refractory in-stent restenosis; Compassionate use.

BACKGROUND: Vascular (VBT) has clearly been shown in multiple clinical trials to decrease restenosis rates for in-stent restenosis (ISR). However, patients enrolled in these randomized clinical trials represent a select group, and the efficacy of VBT in patients with ISR who were excluded from these controlled trials due to more complex coronary anatomy requires further investigation. This study sought to define the angiographic and clinical profile and outcomes of these high-risk patients with ISR who were excluded from the randomized clinical trials and who received VBTusing Strontium-90 (Sr-90) using the Novoste Beta-Cath System through a Compassionate Use Protocol (CUP). METHODS: The study was designed as a single center, prospective, open label registry trial evaluating the use of VBT on complex instent restenotic lesions in patients who were excluded from the START and START 40 trials. In general, these patients included those with saphenous vein graft (SVG) lesions, long lesions (>35 mm), and patients with a history of more than three prior interventions. VBT using Sr-90 was delivered using the Novoste Beta-Cath System after successful angioplasty. The predetermined primary endpoint was freedom from target vessel revascularization (TVR) at 8 months, one and two years. The secondary endpoint was a composite of death, myocardial infarction (MI) and TVR at 8 months, one year, and two years. RESULTS: Between September 4, 1998 and December 6, 2000, 32 patients were treated with VBT under the UCP protocol. The mean duration of follow up was 15.3 +/- 8.3 months. There were 9 major cardiac events at eight months including one death, one acute myocardial infarction and 7 TVR. Excluding the one patient who died, 33 lesions were available for follow-up. The rate of TVR in this high-risk patient population was 21.1% (n = 7/33 lesions). The method of revascularization included one bypass surgery and 6 repeat percutaneous coronary interventions. CONCLUSIONS: This trial demonstrates that utilization of the Beta-Cath System using Sr-90 for the treatment of ISR in a patient population excluded from the randomized clinical trials due to unfavorable lesions characteristics is feasible appears to be associated TVR rates that compare favorably with the event rates of patients enrolled in other trials enrolling lower-risk groups.

Aged↗
PubMedDate not supplied

Clinical and angiographic profile of patients with markedly elevated coronary calcium scores (>or=1000) detected by electron beam computed tomography.

OBJECTIVE: The objective of this study was to determine the clinical and angiographic profile of patients with extremely high coronary artery calcium scores (CACS; >or=1000) by electron beam computed tomography (EBCT). METHODS: All patients at Rush University Medical Center who had a calcium score >or=1000 and a coronary angiogram performed from 1997 to 2002 were identified using a prospectively collected database. The baseline demographics, symptom status, and degree of coronary stenosis by angiography and subsequent rate of coronary intervention were compared with that of patients with calcium scores <1000. RESULTS: The clinical and angiographic profile of patients with severe coronary calcification, detected by EBCT, revealed that patients with scores >or=1000 had a significantly higher prevalence of coronary stenosis >or=50% compared with patients with scores <1000 (97% vs. 57%, P<.001). The group with CACS >or=1000 was more likely to be male (90% vs. 75%, P=.027) and was older (64+/-8 vs. 59+/-10, P=.001) compared with the group with less severe calcification. Although there was a significantly higher rate of luminal stenosis detected by coronary angiography in the cohort with CACS >or=1000, there was no difference in subsequent percutaneous coronary intervention (PCI) and utilization of intracoronary stents between the two groups. CONCLUSIONS: A markedly elevated coronary calcium score (>or=1000) is correlated with increasing age and is associated with an increased likelihood of coronary stenosis >or=50%. However, the decision to perform coronary angiography in patients with severe coronary calcification should not be based solely on these findings, but should remain primarily dependent on the degree of ischemia detected by clinical and functional assessment.

Aged↗
PubMedDate not supplied

The effect of percutaneous transmyocardial laser revascularization on left ventricular function in a porcine model of hibernating myocardium: a pilot study.

BACKGROUND: Hibernating myocardium is defined as a state of persistently impaired myocardial function at rest due to reduced coronary blood flow that can partially or completely be restored to normal if the myocardial oxygen supply/demand relationship is favorably altered. Percutaneous laser revascularization (PMR) is an emerging catheter-based technique that involves creating channels in the myocardium, directly through a percutaneous approach with a laser delivery system, and has been shown to reduce symptoms in patients with severe refractory angina; however, its effect on improving regional wall motion abnormalities in hibernating myocardium has not been clearly established. We sought to determine the effect of PMR using the Eclipse System (Cardiogenesis) on left ventricular function in a porcine model of hibernating myocardium. METHODS: A model of hibernating myocardium was created by placement of an ameroid constrictor in the proximal left anterior descending artery of a 35 kg male Yorkshire pig. The presence of hibernating myocardium was confirmed with dobutamine stress echocardiography (DSE) and defined as severe hypocontractility at rest, with an improvement in systolic wall thickening with low-dose dobutamine in myocardial regions with a subsequent deterioration in function at peak stress (biphasic response). After the demonstration of hibernating myocardium, PMR was performed in the area of hypocontractile function, and the serial echocardiography was performed. The echocardiograms were reviewed by an experienced echocardiologist blinded to the results, and regional wall motion was assessed using the American Society of Echocardiography Wall Motion Score. Six weeks after PMR, the animal was sacrificed and the heart sent for histopathologic studies. RESULTS: A comparison of the regional wall motion function of the area distal to the ameroid constrictor and in the contralateral wall at baseline, post-ameroid placement, and post-PMR was performed. Hibernating myocardium was demonstrated 4 weeks after ameroid placement by DSE. Coronary angiography demonstrated a discrete 90%stenosis in the proximal LAD at the site of ameroid constrictor placement without evidence of collaterals. Using PMR, 17 bursts were successfully delivered to the anterior wall distal to the ameroid constrictor. Four weeks after PMR, there was improvement in wall motion function in the region distal to the ameroid placement by echocardiography. Histopathologic analysis demonstrated the absence of myocardial infarction in the anterior wall distal to the ameroid constrictor. CONCLUSIONS: The performance of PMR in a porcine model of hibernating myocardium is feasible and is associated with an improvement regional wall motion function after 4 weeks.

Animals↗
PubMedDate not supplied

Clinical and angiographic outcomes of cardiac transplant patients treated with intracoronary beta-radiation for in-stent restenosis: a case series.

BACKGROUND: Vascular brachytherapy (VBT) is effective for the treatment of in-stent restenosis (ISR), however, the effect of VBT clinical and angiographic outcomes of patients with ISR who have undergone orthotopic heart transplantation (OHT) requires further study. METHODS: All OHT patients with ISR treated with VBT using the Novoste Beta-Cath System at Rush University Medical Center were identified, and the clinical and angiographic outcomes were evaluated. RESULTS: Four OHT patients with ISR who underwent VBT were identified. The mean age was 48.5 years, and the mean duration posttransplantation was 7.5 years. The mean reference coronary vessel diameter was 3.06 mm. The primary interventional device utilized prior to VBT was cutting balloon angioplasty (CBA) in 75% and percutaneous balloon angioplasty in 25%. The mean duration of follow-up after VBT was 11 months. There were no deaths attributable due to cardiac disease, no myocardial infarction, and no target vessel revascularization on follow-up. Overall survival during this period was 75%, with one mortality due to stroke 8 months after VBT. CONCLUSIONS: VBT for the treatment of ISR in patients who have undergone OHT appears safe and feasible and is associated with acceptable clinical and angiographic outcomes.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Clinical outcomes of patients treated with the cutting balloon and Sr-90 beta-irradiation for instent restenosis.

BACKGROUND: The cutting balloon (CB) is an emerging therapy for the treatment of instent restenosis (ISR), but its impact on the clinical outcomes of patients treated with intracoronary radiation therapy (IRT) with Sr-90 compared with conventional PTCA and IRT is not clearly defined. METHODS: We compared the baseline demographics, angiographic characteristics and clinical outcomes of 102 consecutive patients with ISR treated either with CB+IRT (n=45) or with conventional PTCA+IRT (n=57). The combined endpoint was the occurrence of major adverse cardiac events (MACE), which was defined as a composite of death, myocardial infarction (MI) or target vessel revascularization (TVR) at 6 months. RESULTS: The CB+IRT group had a shorter mean lesion length (14.3+/-6.5 vs. 21.1+/-15.7, P=.009), and greater utilization of glycoprotein IIb/IIIa inhibitors during the procedure (48.9% vs. 26.3%, P=.02) compared to the PTCA+IRT group. There were no significant differences in the baseline demographics, angiographic and procedural results, or subsequent MACE at 6 months between the two groups. CONCLUSION: The strategy of CB+IRT using Sr-90 for ISR is associated with similar procedural and clinical outcomes compared to conventional PTCA+IRT. Further study is warranted to determine which patient subgroups would derive the most benefit from this approach.

Aged↗
PubMedDate not supplied

Visual assessment of procedural results following treatment with Sr-90 beta-radiation for instent restenosis.

BACKGROUND: Visual assessment (VA) of postprocedural % diameter stenosis (DS) is used routinely in clinical practice to determine the adequacy of coronary intervention. Although VA has been shown to underestimate final %DS after balloon angioplasty compared to quantitative coronary angiography (QCA), the impact of this effect on clinical outcomes following treatment with intracoronary radiation therapy (IRT) with Sr-90 for instent restenosis (ISR) is unknown. METHODS: To determine the effect of VA on the rate of major adverse cardiac events (MACEs) after IRT for ISR, we compared the clinical outcomes of 102 consecutive patients based on postprocedural %DS by QCA vs. %DS by VA. MACE was defined as death, M1 or need for target vessel revascularization (TVR). RESULTS: MACE rates for the 102 consecutive patients grouped according to postprocedural %DS by QCA and VA were compared. The mean %DS by QCA was 30.7%, while the mean %DS by VA was 12.5%. The mean %DS by VA across the QCA subgroups were 13.67%, 10.71% and 13.37%, respectively (P = .244). Fifty-two patients (51.0%) had %DS > 30% by QCA with the highest MACE percentage occurring in this subgroup. CONCLUSION: VA underestimated the %DS compared to QCA, and it was associated with worse MACE following treatment with Sr-90 for ISR.

Beta Particles↗