PubMed Health⌕ Search

Biomedical subjects

I F Palacios

Publications and source records attributed to I F Palacios.

At least 37 records · Page 2Linked to original sources

Closure of patent foramen ovale for paradoxical emboli: intermediate-term risk of recurrent neurological events following transcatheter device placement.

OBJECTIVES: We report the largest and the longest follow-up to date of patients who underwent transcatheter patent foramen ovale (PFO) closure for paradoxical embolism. BACKGROUND: Closure of a PFO has been proposed as an alternative to anticoagulation in patients with presumed paradoxical emboli. METHODS: Data were collected for patients following PFO closure with the Clamshell, CardioSEAL or Buttoned Devices at two institutions. RESULTS: There were 63 patients (46 +/- 18 years) with a follow-up of 2.6 +/- 2.4 years. Fifty-four (86%) had effective closure of the foramen ovale (trivial or no residual shunt by echocardiography) while seven (11%) had mild and two (3%) had moderate residual shunting. There were four deaths (leukemia, pulmonary embolism, sepsis following a hip fracture and lung cancer). There were four recurrent embolic neurological events following device placement: one stroke and three transient events. The stroke occurred in a 56-year-old patient six months following device placement. A follow-up transesophageal echocardiogram showed a well seated device without residual shunting. Two of the four events were associated with suboptimal device performance (one patient had a significant residual shunt and a second patient had a "friction lesion" in the left atrial wall associated with a displaced fractured device arm). The risk of recurrent stroke or transient neurological event following device placement was 3.2% per year for all patients. CONCLUSION: Transcatheter closure of PFO is an alternative therapy for paradoxical emboli in selected patients. Improved device performance may reduce the risk of recurrent neurological events. Further studies are needed to identify patients most likely to benefit from this intervention.

Adult↗

The place of directional coronary atherectomy for the treatment of in-stent restenosis.

The beneficial short and long-term results of coronary stenting have resulted in a dramatic increase in stent utilization, accounting for greater than 80% of coronary interventions [1--9]. However, the long-term beneficial effect of coronary stenting is limited by the occurrence of a 14 to 61% restenosis rate [10--13]. The optimal percutaneous revascularization strategy for the treatment of in-stent restenosis remains undetermined. Although balloon angioplasty has been performed with high initial procedural success, the long-term results are disappointing due to significant recurrence [14--18]. In this article we describe the feasibility, safety, immediate and long-term outcome of directional coronary atherectomy (DCA) as a treatment modality in a cohort of patients undergoing percutaneous intervention for the treatment of in-stent restenosis at the Massachusetts General Hospital.

Aged↗

Histopathologic comparison of human coronary in-stent and post-balloon angioplasty restenotic tissue.

Histomorphometric studies for smooth muscle cells, macrophages, tissue factor, collagen, and cell proliferation were performed on 20 atherectomy specimens from patients with in-stent restenosis and 20 specimens from patients with post-balloon PTCA restenosis. Smooth muscle cell content was larger and proliferation index was higher in in-stent restenotic tissue; macrophage, tissue factor, and collagen content were larger in post-balloon percutaneous transluminal coronary angioplasty restenotic tissue, suggesting a more cellular and proliferative response with less thrombogenic potential in human tissue from in-stent restenosis than tissue from post-balloon percutaneous transluminal coronary angioplasty restenosis.

Aged↗

Comparison of immediate and long-term results of mitral balloon valvotomy with the double-balloon versus Inoue techniques.

There is controversy as to whether the double-balloon or Inoue technique of percutaneous mitral balloon valvotomy (PMBV) provides superior immediate and long-term results. This study compares the immediate procedural and long-term outcomes of patients undergoing PMBV using the double-balloon versus the Inoue techniques. Seven hundred thirty-four consecutive patients who underwent PMBV using the double-balloon (n = 621) or Inoue technique (n = 113) were studied. There were no statistically significant differences in baseline clinical and morphologic characteristics between the double-balloon and Inoue patients. The double-balloon technique resulted in superior immediate outcome, as reflected in a larger post-PMBV mitral valve area (1.9 +/- 0.7 vs 1.7 +/- 0.6 cm2; p = 0.005) and a lower incidence of 3+ mitral regurgitation after PMBV (5.4% vs 10.6%; p = 0.05). This superior immediate outcome of the double-balloon technique was observed only in the group of patients with echocardiographic score < or = 8 (post-PMBV mitral valve areas 2.1 +/- 0.7 vs 1.8 +/- 0.6; p = 0.004). Despite the difference in immediate outcome, there were no significant differences in event-free survival at long-term follow-up between the 2 techniques. Our study demonstrates that compared with the Inoue technique, the double-balloon technique results in a larger mitral valve area and less degree of severe mitral regurgitation after PMBV. Despite the difference in immediate outcome between both techniques, there were no significant differences in event-free survival at long-term follow-up.

Aged↗

Echocardiography can predict the development of severe mitral regurgitation after percutaneous mitral valvuloplasty by the Inoue technique.

Severe mitral regurgitation (MR) following mitral balloon valvuloplasty is a major complication of this procedure. We recently described a new echocardiographic score that can predict the development of severe MR following mitral valvuloplasty with the double balloon technique. The present study was designed to test the usefulness of this score for predicting severe MR in patients undergoing the procedure using the Inoue balloon technique. From 117 consecutive patients who underwent mitral valvuloplasty using the Inoue technique, 14 (11.9%) developed severe MR after the procedure. A good quality echocardiogram before mitral valvuloplasty was available in 11 patients. These 11 patients were matched by age, sex, mitral valve area, and degree of MR before valvuloplasty with 69 randomly selected patients who did not develop severe MR after Inoue valvuloplasty. The total MR-echocardiographic (MR-echo) score was significantly greater in the severe MR group (10.5 +/- 1.4 vs 8.2 +/- 1.1; p <0.001). In addition, the component grades for the anterior leaflet (2.9 +/- 0.5 vs 2.2 +/- 0.4; p <0.001), posterior leaflet (2.6 +/- 0.7 vs 1.9 +/- 0.8), commissures (2.4 +/- 0.8 vs 2.0 +/- 0.5; p <0.05) and subvalvular apparatus (2.6 +/- 0.5 vs 1.9 +/- 0.4; p <0.001) were also higher in the MR group. Using a total score of > or = 10 as a cut-off point for predicting severe MR with the Inoue technique, a sensitivity of 82%, specificity of 91%, accuracy of 90%, and negative predictive value of 97% were obtained. Stepwise logistic regression analysis identified the MR-echo score as the only independent predictor for developing severe MR with the Inoue technique (p <0.0001). Thus, the MR-echo score can also predict the development of severe MR following mitral balloon valvuloplasty using the Inoue technique.

Catheterization↗

Risk predictors in patients scheduled for percutaneous coronary revascularization.

Traditionally, procedural risks associated with conventional balloon coronary angioplasty have been largely attributed to unfavorable lesion morphology. However, factors predicting adverse events in the current practice of percutaneous coronary revascularization are unclear. The present study was undertaken to determine factors predicting major adverse events (death or Q-wave myocardial infarction or emergency bypass surgery) in 3,335 consecutive patients undergoing percutaneous coronary revascularization in the current practice of percutaneous coronary revascularization. During the period of observation, the rate of lesions treated successfully increased from 91% to 95% (P < 0.0001), whereas the rate of major adverse events (MACE) decreased from 3.6% to 1.6% (odds ratio [OR], 0.70 per year). Using multiple stepwise logistic regression analysis, cardiogenic shock (OR, 8.59; confidence interval [CI], 4.27-17.27), renal disease (OR, 3.33; CI, 1.95-5.69), evolving myocardial infarction (OR, 2.80; CI, 1.47-5.31), congestive heart failure (OR, 2.18; CI, 1.23-3.86), total number of lesions treated (OR, 1.28; CI, 1.03-1.59), age (OR, 1.03; CI, 1.01-1.06), and history of prior coronary intervention (OR, 0.51; CI 0.26-0.99) were identified as independent predictors of MACE. In addition, vascular disease (OR, 2. 48; CI 1.37-4.50) and unstable angina pectoris (OR, 0.44; CI 0.25-0. 79) were related to adverse events when patients in cardiogenic shock were excluded from the model. With the exception of most unfavorable lesion morphology (AHA/ACC lesion type C; OR, 2.05; CI, 1.19-3.52), anatomic parameters added no further information. In the present era of device technology, success rates of percutaneous coronary revascularization procedures have increased and remain to be determined by lesion morphology. In contrast, the rate of MACE is declining and best predicted by easily identified patient characteristics.

Aged↗

Ventricular remodeling in active myocarditis. Myocarditis Treatment Trial.

BACKGROUND: Remodeling of the left ventricle with the development of a spherical cavity occurs in dilated cardiomyopathy and is associated with a poor long-term prognosis. The early effects of myocarditis on left ventricular geometry have not been previously described or correlated with clinical outcome. METHODS: The baseline echocardiograms of 35 patients with biopsy-confirmed myocarditis were compared with 20 normal controls. Left ventricular end-diastolic volume, long axis length, and mid-cavity diameter were measured. The degree of sphericity was expressed as the ratio of the mid-cavity diameter to the long axis length. Left ventricular ejection fraction was assessed by radionuclide angiography. RESULTS: In patients with myocarditis, mean left ventricular volume of 81 +/- 29 mL/m(2) was significantly greater than 50 +/- 8 mL/m(2) in controls (P =.001). Chamber dilatation occurred primarily along the mid-cavity diameter, which measured 5.3 +/- 0.8 cm in patients with myocarditis versus 4.2 +/- 0.4 cm in controls (P =.001). The degree of left ventricular sphericity in patients with myocarditis, 0.64 +/- 0.08, was significantly greater than that of controls, 0.54 +/- 0.04 (P =.001). When patients were stratified according to left ventricular volume, patients with increased left ventricular volume (>75 mL/m(2)) were associated with a more spherical chamber and lower left ventricular ejection fraction than patients with a more normal left ventricular volume (</=75 mL/m(2)). CONCLUSIONS: Active myocarditis is associated with early left ventricular remodeling and the development of a spherical chamber. These changes correlate with ventricular dilatation and reduced left ventricular ejection fraction.

Adult↗

Is redo percutaneous mitral balloon valvuloplasty (PMV) indicated in patients with post-PMV mitral restenosis?

OBJECTIVES: The purpose of this study was to assess the immediate and long-term outcome of repeat percutaneous mitral balloon valvuloplasty (PMV) for post-PMV mitral restenosis. BACKGROUND: Symptomatic mitral restenosis develop in 7% to 21% of patients after PMV. Currently, most of these patients are referred for mitral valve replacement. However, it is unknown if these patients may benefit from repeat PMV. METHODS: We report the immediate outcome and long-term clinical follow-up results of 36 patients (mean age 58+/-13 years, 75% women) with symptomatic mitral restenosis after prior PMV, who were treated with a repeat PMV at 34.6+/-28 months after the initial PMV. The mean follow-up period was 30+/-33 months with a maximal follow-up of 10 years. RESULTS: An immediate procedural success was obtained in 75% patients. The overall survival rate was 74%, 72% and 71% at one, two, and three years respectively. The event-free survival rate was 61%, 54% and 47% at one, two, and three years respectively. In the presence of comorbid diseases (cardiac and noncardiac) the two-year event-free survival was reduced to 29% as compared with 86% in patients without comorbid diseases. Cox regression analysis identified the echocardiographic score (p = 0.03), post-PMV mitral valve area (p = 0.003), post-PMV mitral regurgitation grade (p = 0.02) and post-PMV pulmonary artery pressure (p = 0.0001) as independent predictors of event-free survival after repeat PMV. CONCLUSIONS: Repeat PMV for post-PMV mitral restenosis results in good immediate and long-term outcome in patients with low echocardiographic scores and absence of comorbid diseases. Although the results are less favorable in patients with suboptimal characteristics, repeat PMV has a palliative role if the patients are not surgical candidates.

Aged↗

Implications of small reference vessel diameter in patients undergoing percutaneous coronary revascularization.

OBJECTIVES: The purpose of this study was to determine whether small reference diameter of the culprit coronary artery influences the outcome of an attempted percutaneous revascularization procedure in the current era of interventional cardiology. BACKGROUND: Although the interventional strategy is largely determined by the size of the culprit coronary artery, earlier quantitative studies have not shown a worse acute outcome for small reference vessel diameter (< or =2.5 mm). METHODS: A total of 2,306 patients undergoing percutaneous coronary revascularization was divided in groups with reference diameters < or =2.5 mm (n = 813) or >2.5 mm (n = 1,493). Success and in-hospital major adverse cardiac event (death, Q-wave myocardial infarction and emergency coronary artery bypass graft) rates between both groups were compared. RESULTS: Patients with lesions in small vessels were older and presented more frequently with female gender, diabetes mellitus, heart failure, peripheral vascular, multivessel coronary disease and American Heart Association/American College of Cardiology (AHA/ACC) lesion type C (p < or = 0.01, each). Further, utilization of interventional devices differed markedly. In contrast to stents (18.5% vs. 41.9%) and directional atherectomy (3.7% vs. 13.5%), conventional balloon angioplasty (73% vs. 50%) and rotational atherectomy (16.1% vs. 8.3%) were used more often in smaller vessels (p < or = 0.0001, each). Success rate was lower in the small vessel group (92% vs. 95%; p = 0.006). Major adverse cardiac events occurred more frequently in small than large vessels (univariate 3.4% vs. 2.0%, p = 0.03; multivariate odds ratio 2.1, p = 0.02), particularly when proximal coronary segments were compared. CONCLUSIONS: Lesions in vessels with small reference diameter represent a distinct group with respect to clinical and morphologic characteristics as well as device utilization. These lesions have lower chances of successful percutaneous intervention and carry relatively higher risks, specifically when located in proximal coronary segments.

Aged↗

Mitral balloon valvotomy for patients with mitral stenosis in atrial fibrillation: immediate and long-term results.

OBJECTIVES: The purpose of this study was to examine the effect of atrial fibrillation (AF) on the immediate and long-term outcome of patients undergoing percutaneous mitral balloon valvuloplasty (PMV). BACKGROUND: There is controversy as to whether the presence of AF has a direct negative effect on the outcome after PMV. METHODS: The immediate procedural and the long-term clinical outcome after PMV of 355 patients with AF were prospectively collected and compared with those of 379 patients in normal sinus rhythm (NSR). RESULTS: Patients with AF were older (62 +/- 12 vs. 48 +/- 14 years; p < 0.0001) and presented more frequently with New York Heart Association (NYHA) class IV (18.3% vs. 7.9%; p < 0.0001), echocardiographic score >8 (40.1% vs. 25.1%; p < 0.0001), calcified valves under fluoroscopy (32.4% vs. 18.8%, p < 0.0001) and with history of previous surgical commissurotomy (21.7% vs. 16.4%; p = 0.0002). In patients with AF, PMV resulted in inferior immediate and long-term outcomes, as reflected in a smaller post-PMV mitral valve area (1.7 +/- 0.7 vs. 2 +/- 0.7 cm2; p < 0.0001) and a lower event free survival (freedom of death, redo-PMV and mitral valve surgery) at a mean follow-up time of 60 months (32% vs. 61%; p < 0.0001). In the group of patients in AF, severe post-PMV mitral regurgitation (> or =3+) (p = 0.0001), echocardiographic score >8 (p = 0.004) and pre-PMV NYHA class IV (p = 0.046) were identified as independent predictors of combined events at follow-up. CONCLUSIONS: Patients with AF have a worse immediate and long-term outcomes after PMV. However, the presence of AF by itself does not unfavorably influence the outcome, but is a marker for clinical and morphologic features associated with inferior results after PMV.

Adult↗

Tissue characteristics of restenosis after percutaneous transluminal coronary angioplasty in diabetic patients.

OBJECTIVES: The purposes of this study were to analyze coronary specimens from patients with diabetes mellitus (DM) and to compare them with specimens from patients without DM. BACKGROUND: Diabetes mellitus is associated with an increased incidence of restenosis after percutaneous transluminal coronary angioplasty (PTCA). Increased hypercellular smooth muscle cell proliferation with exaggerated intimal hyperplasia formation may be responsible for this predisposition. METHODS: Eighteen coronary atherectomy specimens with restenosis after PTCA from patients with DM were compared with 18 coronary atherectomy specimens with restenosis after PTCA from patients without DM. Total and segmental areas were quantified on trichrome-stained tissue of hypercellular tissue, collagen-rich sclerotic tissue, atheroma and thrombus. Demographic and angiographic data were similar in both groups. RESULTS: The percentage of total plaque area composed of hypercellular tissue was lower in restenotic specimens from patients with DM than in restenotic specimens from patients without DM (19 +/- 6% vs. 44 +/- 5%; p = 0.003). The percentage of collagen-rich sclerotic tissue area was larger in restenotic specimens from patients with DM than in restenotic specimens from patients without DM (77 +/- 9% vs. 53 +/- 4%; p = 0.004). The percentages of atheroma and thrombus were similar in both groups. CONCLUSIONS: Intimal hypercellular tissue content is reduced in restenotic tissue from patients with DM. Collagen-rich sclerotic content is increased in restenotic lesions from patients with DM. These results suggest an accelerated fibrotic rather than a proliferative response in diabetic lesions from patients with restenosis after PTCA.

Aged↗

Directional coronary atherectomy for the treatment of Palmaz-Schatz in-stent restenosis.

Management of in-stent restenosis has become a significant challenge in interventional cardiology. The results of balloon angioplasty have been disappointing due to the high recurrence of restenosis at follow-up. Debulking of the restenotic tissue within the stents using directional coronary atherectomy (DCA) may offer a therapeutic advantage. We report the immediate clinical and angiographic outcomes and long-term clinical follow-up results of 45 patients (46 lesions), mean age 63+/-12 years, 73% men, with a mean reference diameter of 2.9+/-0.6 mm, treated with DCA for symptomatic Palmaz-Schatz in-stent restenosis. DCA was performed successfully in all 46 lesions and resulted in a postprocedural minimal luminal diameter of 2.7+/-0.7 mm and a residual diameter stenosis of 17+/-10%. There were no in-hospital deaths, Q-wave myocardial infarctions, or emergency coronary artery bypass surgeries. Four patients (9%) suffered a non-Q-wave myocardial infarction. Target lesion revascularization was 28.3% at a mean follow-up of 10+/-4.6 months. Kaplan-Meier event-free survival (freedom from death, myocardial infarction, and repeat target lesion revascularization) was 71.2% and 64.7% at 6 and 12 months after DCA, respectively. Thus, DCA is safe and efficacious for the treatment of Palmaz-Schatz in-stent restenosis. It results in a large postprocedural minimal luminal diameter and a low rate of both target lesion revascularization and combined major clinical events at follow-up.

Angioplasty, Balloon↗

Comparison of primary coronary stenting to primary balloon angioplasty with stent bailout for the treatment of patients with acute myocardial infarction.

This study compares the immediate and long-term outcomes of a primary coronary stenting strategy with primary balloon angioplasty with stent bailout in the treatment of patients with acute myocardial infarction (AMI). One hundred forty-seven consecutive patients who underwent primary balloon angioplasty with stent bailout (n = 94) or primary stenting (n = 53) for AMI were clinically followed for 8.1 +/- 5.7 and 8.5 +/- 4.5 months, respectively. Immediate results, as well as in-hospital and long-term ischemic events (death, reinfarction, and repeat revascularization) were compared between both groups. Angiographic success was 91.5% in the balloon angioplasty group and 94% in the stent group. In-hospital and late follow-up combined ischemic events were 22 of 94 (23%) versus 0 of 53 (0%); p < 0.001 and 33 of 78 (42%) versus 13 of 53 (25%), p = 0.04 for the balloon angioplasty and stent groups, respectively. At 6 months, the cumulative probability of repeat target lesion revascularization was higher in the balloon angioplasty group (47% vs 18%, p = 0.0006) as was the probability of late target revascularization (36% vs 18%, p = 0.046); the cumulative event-free survival after 6 months was significantly lower in the balloon angioplasty group (44% vs 80%, p = 0.0001). This study demonstrates that a primary stent placement strategy in patients with AMI is safe, feasible, and superior to primary balloon angioplasty with stent bailout. Primary stenting results in a larger postprocedural minimal luminal diameter, a lower early and late recurrent ischemic event rate, and a lower incidence of target lesion revascularization at follow-up.

Angioplasty, Balloon, Coronary↗

Histopathology of coronary lesions with early loss of minimal luminal diameter after successful percutaneous transluminal coronary angioplasty: is thrombus a significant contributor?

BACKGROUND: Early loss of minimal luminal diameter of >0.3 mm after successful percutaneous transluminal coronary angioplasty (PTCA) is associated with a higher incidence of restenosis. The underlying mechanism of this early loss is unknown and thrombus may be a contributing factor. METHODS: We performed a prospective study using quantitative computerized planimetry on coronary tissue specimens obtained by directional coronary atherectomy of 24 lesions in which early loss occurred 22+/-9 minutes after successful PTCA. RESULTS: Thrombus was present in 9 (37%) of 24 coronary specimens. Segmental areas (mm2) and percentage of total area were distributed as follows: sclerotic tissue, 4.07+/-0.7 mm2 (63%+/-6%); fibrocellular tissue, 0.97+/-0.27 mm2 (16%+/-4%); hypercellular tissue, 0.99+/-0.29 mm2 (12%+/-3%); atheromatous gruel, 0.18+/-0.07 mm2 (3%+/-0.1%); and thrombus, 0.24+/-0.15 mm2 (6%+/-0.4%). There was no difference in the relative early loss index between lesions with or without thrombus (35%+/-7% vs 26%+/-2%, respectively; P= .87). Multiple stepwise regression analysis did not identify any histologic predictors of relative early loss index. CONCLUSION: Histopathologic analysis of coronary lesions with early loss after successful PTCA suggests that thrombus may not play a significant role in this angiographic phenomenon.

Adult↗

Coronary endothelial dysfunction in patients with acute-onset idiopathic dilated cardiomyopathy.

OBJECTIVES: This study sought to determine whether coronary endothelial dysfunction exists in patients with acute-onset idiopathic dilated cardiomyopathy (DCM) and to explore its relation to recovery of left ventricular systolic function in this patient population. BACKGROUND: Coronary endothelial dysfunction exists in chronic DCM, but its importance in the development and progression of ventricular dysfunction is not known. To address this issue we studied coronary endothelial function in patients with idiopathic DCM <6 months in duration and explored the relation between coronary endothelial function and subsequent changes in left ventricular ejection fraction (LVEF). METHODS: Ten patients with acute-onset idiopathic DCM (duration of heart failure symptoms 2.0 +/- 0.4 months [mean +/- SEM]) and 11 control patients with normal left ventricular function underwent assessment of coronary endothelial function during intracoronary administration of the endothelium-dependent vasodilator acetylcholine and the endothelium-independent vasodilator adenosine. Coronary cross-sectional area (CSA) was determined by quantitative coronary angiography and coronary blood flow (CBF) by the product of coronary CSA and CBF velocity measured by an intracoronary Doppler catheter. Patients with DCM underwent assessment of left ventricular function before and several months after the study. RESULTS: Acetylcholine infusion produced no change in coronary CSA in control patients but significant epicardial constriction in patients with DCM (-36 +/- 11%, p < 0.01). These changes were associated with increases in CBF in control patients (+118 +/- 49%, p < 0.01) but no change in patients with DCM. Infusion of adenosine produced increases in coronary caliber and blood flow in both groups. Follow-up assessment of left ventricular function was obtained in nine patients with DCM 7.0 +/- 1.7 months after initial study, at which time LVEF had improved by > or =0.10 in four patients. Multiple linear regression revealed a positive correlation between both the coronary CSA (r2 = 0.57, p < 0.05) and CBF (r2 = 0.68, p < 0.01) response to acetylcholine and the subsequent improvement in LVEF. CONCLUSIONS: Coronary endothelial dysfunction exists at both the microvascular and the epicardial level in patients with acute-onset idiopathic DCM. The preservation of coronary endothelial function in this population is associated with subsequent improvement in left ventricular function.

Acetylcholine↗

Optimal coronary balloon angioplasty with provisional stenting versus primary stent (OCBAS): immediate and long-term follow-up results.

OBJECTIVE: This study sought to compare two strategies of revascularization in patients obtaining a good immediate angiographic result after percutaneous transluminal coronary angioplasty (PTCA): elective stenting versus optimal PTCA. A good immediate angiographic result with provisional stenting was considered to occur only if early loss in minimal luminal diameter (MLD) was documented at 30 min post-PTCA angiography. BACKGROUND: Coronary stenting reduces restenosis in lesions exhibiting early deterioration (>0.3 mm) in MLD within the first 24 hours (early loss) after successful PTCA. Lesions with no early loss after PTCA have a low restenosis rate. METHODS: To compare angiographic restenosis and target vessel revascularization (TVR) of lesions treated with coronary stenting versus those treated with optimal PTCA, 116 patients were randomized to stent (n=57) or to optimal PTCA (n=59). After randomization in the PTCA group, 13.5% of the patients crossed over to stent due to early loss (provisional stenting). RESULTS: Baseline demographic and angiographic characteristics were similar in both groups of patients. At 7.6 months, 96.6% of the entire population had a follow-up angiographic study: 98.2% in the stent and 94.9% in the PTCA group. Immediate and follow-up angiographic data showed that acute gain was significantly higher in the stent than in the PTCA group (1.95 vs. 1.5 mm; p < 0.03). However, late loss was significantly higher in the stent than the PTCA group (0.63+/-0.59 vs. 0.26+/-0.44, respectively; p=0.01). Hence, net gain with both techniques was similar (1.32< or =0.3 vs. 1.24+/-0.29 mm for the stent and the PTCA groups, respectively; p=NS). Angiographic restenosis rate at follow-up (19.2% in stent vs. 16.4% in PTCA; p=NS) and TVR (17.5% in stent vs. 13.5% in PTCA; p=NS) were similar. Furthermore, event-free survival was 80.8% in the stent versus 83.1% in the PTCA group (p=NS). Overall costs (hospital and follow-up) were US $591,740 in the stent versus US $398,480 in the PTCA group (p < 0.02). CONCLUSIONS: The strategy of PTCA with delay angiogram and provisional stent if early loss occurs had similar restenosis rate and TVR, but lower cost than primary stenting after PTCA.

Angioplasty, Balloon, Coronary↗

Restoration of coronary flow in myocardial infarction by intravenous chimeric 7E3 antibody without exogenous plasminogen activators. Observations in animals and humans.

BACKGROUND: Coronary thrombus is composed of platelets and fibrin, and during thrombolytic treatment, reflow may be slowed by platelet deposition. It may be possible to initiate coronary reflow without exogenous plasminogen activators by blocking platelet aggregation while fibrin generation is impeded with heparin. METHODS AND RESULTS: In 14 dogs, left anterior descending coronary artery thrombosis was produced by endothelial trauma and thrombin instillation in the presence of stenosis distally. Reflow was monitored by flow probe during treatment with (1) heparin, (2) heparin and aspirin, and (3) heparin, aspirin, and intravenous 7E3. Eighty percent of dogs treated with the third combination showed stable reflow (> or = 25% of prestenotic flow) in 50 +/- 9 minutes. In addition, 13 patients were studied during intravenous administration of c7E3 10 minutes before primary angioplasty for acute myocardial infarction and Thrombolysis In Myocardial Infarction (TIMI) grade 0 or 1 flow. Pretreatment included heparin and oral aspirin. Flow increased during a 10-minute period by at least one TIMI grade in 11 (85%) of 13 and reached TIMI grade 2 or 3 in 7 (54%) of 13 patients. Average TIMI grade flow increased from 0.31 +/- 0.5 to 1.54 +/- 0.8 (P < .001). Thrombus length 10 minutes after c7E3 was 5.1 +/- 3.5 mm. All but 1 patient then underwent angioplasty. There were no complications. CONCLUSIONS: Coronary reflow can be initiated by intravenous 7E3 administration in the presence of heparin and aspirin. In human patients, this flow can be observed in 10 minutes without exogenous thrombolytic agents.

Abciximab↗