Randomized evaluation of two drug-eluting stents with identical metallic platform and biodegradable polymer but different agents (paclitaxel or sirolimus) compared against bare stents: 1-year results of the PAINT trial.

OBJECTIVES: We tested two novel drug-eluting stents (DES), covered with a biodegradable-polymer carrier and releasing paclitaxel or sirolimus, which were compared against a bare metal stent (primary objective). The DES differed by the drug, but were identical otherwise, allowing to compare the anti-restenosis effects of sirolimus versus paclitaxel (secondary objective). BACKGROUND: The efficacy of novel DES with biodegradable polymers should be tested in the context of randomized trials, even when using drugs known to be effective, such as sirolimus and paclitaxel. METHODS: Overall, 274 patients with de novo coronary lesions in native vessels scheduled for stent implantation were randomly assigned (2:2:1 ratio) for the paclitaxel (n = 111), sirolimus (n = 106), or bare metal stent (n = 57) groups. Angiographic follow-up was obtained at 9 months and major cardiac adverse events up to 12 months. RESULTS: Both paclitaxel and sirolimus stents reduced the 9-month in-stent late loss (0.54-0.44 mm, 0.32-0.43 mm, vs. 0.90-0.45 mm respectively), and 1-year risk of target vessel revascularization and combined major adverse cardiac events (P < 0.05 for both, in all comparisons), compared with controls. Sirolimus stents had lower late loss than paclitaxel stents (P < 0.01), but similar 1-year clinical outcomes. There were no differences in the risk of death, infarction, or stent thrombosis among the study groups. CONCLUSION: Both novel DES were effective in reducing neointimal hyperplasia and 1-year re-intervention, compared to bare metal stents. Our findings also suggest that sirolimus is more effective than paclitaxel in reducing angiographic neointima, although this effect was not associated with better clinical outcomes.

Coronary revascularization (surgical or percutaneous) decreases mortality after the first year in diabetic subjects but not in nondiabetic subjects with multivessel disease: an analysis from the Medicine, Angioplasty, or Surgery Study (MASS II).

BACKGROUND: It is currently unknown whether revascularization procedures are associated with an improvement in mortality among diabetic subjects, as compared with a more conservative medical treatment. METHODS AND RESULTS: In MASS II, a total of 611 patients with stable multivessel coronary disease were randomly assigned to medical treatment, surgery, or angioplasty. From these, 190 patients had diabetes (medical, 75 patients; angioplasty, 56 patients; surgery, 59 patients) and comprised the present study population. Mortality rates were analyzed for the entire 5 years of follow-up. Separate analyzes were also performed for mortality at 2 time intervals: during the first year and after the first year of follow-up. We calculated the probability of death conditional on surviving to the start of the interval analyzed. The cumulative 5-year mortality as well as the mortality during the first year of follow-up was not significantly different among treatment groups, both for diabetic and for nondiabetic subjects. Also, during years 2 to 5, the mortality of the 3 treatment groups was not different for nondiabetic subjects. Among diabetic subjects, however, patients randomized to angioplasty or surgery had a significantly lower mortality between years 2 and 5 than those allocated to medical treatment (P=0.039). CONCLUSIONS: Surgery, angioplasty, and medical treatment appear to be associated with similar mortality rates for non-diabetic subjects. For diabetic subjects, however, coronary revascularization (percutaneous or surgical) significantly decreased the risk of death after the first year and up to 5 years, compared with medical treatment alone.

A new paradigm for plaque stabilization.

The concept of plaque stabilization was developed to explain how lipid lowering could decrease adverse coronary events without a substantial reduction in the regression of atherosclerosis. Plaques were stabilized by reducing serum cholesterol leading to several favorable pathobiological changes in the vessel wall of lipid-rich plaques responsible for a majority of acute coronary events. However, this concept is limited for several reasons including that it does not incorporate strategies directed against either plaques that have already destabilized or non-lipid-rich plaques, which are the substrate for at least one third of major coronary thrombi and may or may not be stabilized by lipid lowering. For the destabilized plaque with overlying thrombus, either percutaneous intervention, long-term antithrombotic and/or anticoagulant therapy, or possibly aggressive lipid lowering stabilizes lesions by reducing subsequent thrombosis at the lesion site and, at least with lipid lowering, by improving endothelial function and possibly reducing inflammation. Short-term, in-hospital antithrombotic approaches alone with agents like the GP platelet IIb/IIIa inhibitors have not been effective in this situation. For other plaques not presently destabilized, the main goal of therapy is reducing future acute coronary events. Several classes of drugs, including ACE inhibitors, beta-blockers, and antithrombotic agents in addition to lipid-lowering agents, reduce events, and this may be attributable, at least in part, to plaque-stabilizing effects.

Luminal recovery from six to twelve months after implantation of "thicker strut" coronary stents.

A group of 50 patients with 51 de novo lesions treated with thicker strut stents (strut thickness >100 microm) was angiographically evaluated at baseline, after stenting, and at 6 and 12 months. Minimal luminal diameter (MLD) significantly increased from 6 to 12 months (6 months: 1.72 +/- 0.50 mm vs 12 months: 1.81 +/- 0.47 mm; p <0.01). The binary restenosis (diameter stenosis >50%) rate was 17% at 6 months and 11% at 12 months (p = NS). At multivariate analysis, lumen loss at 6 months (p = 0.018) and deployment pressure (p = 0.041) independently predicted the changes in MLD between 6 and 12 months.

Evaluation of plaque composition by intravascular ultrasound "virtual histology": the impact of dense calcium on the measurement of necrotic tissue.

AIMS: We aimed to evaluate if the co-localisation of calcium and necrosis in intravascular ultrasound virtual histology (IVUS-VH) is due to artefact, and whether this effect can be mathematically estimated. METHODS AND RESULTS: We hypothesised that, in case calcium induces an artefactual coding of necrosis, any addition in calcium content would generate an artificial increment in the necrotic tissue. Stent struts were used to simulate the "added calcium". The change in the amount and in the spatial localisation of necrotic tissue was evaluated before and after stenting (n=17 coronary lesions) by means of a especially developed imaging software. The area of "calcium" increased from a median of 0.04 mm2 at baseline to 0.76 mm2 after stenting (p<0.01). In parallel the median necrotic content increased from 0.19 mm2 to 0.59 mm2 (p<0.01). The "added" calcium strongly predicted a proportional increase in necrosis-coded tissue in the areas surrounding the calcium-like spots (model R2=0.70; p<0.001). CONCLUSIONS: Artificial addition of calcium-like elements to the atherosclerotic plaque led to an increase in necrotic tissue in virtual histology that is probably artefactual. The overestimation of necrotic tissue by calcium strictly followed a linear pattern, indicating that it may be amenable to mathematical correction.

Noninvasive assessment of patients undergoing percutaneous intervention in myocardial infarction.

BACKGROUND: Restenosis after primary percutaneous coronary intervention (PPCI) remains an important clinical problem, even with stent implantation. The ability of noninvasive testing to diagnose restenosis has had only inconsistent demonstration. OBJECTIVE: Our objective was to evaluate the ability of exercise treadmill testing (ETT) and myocardial perfusion imaging (MPI) to diagnose restenosis in patients treated by PPCI within 12 hours of ST-elevation myocardial infarction (STEMI). METHODS: From August 2003 to January 2006, 64 patients (mean age of 56.2±10.2 years, 53 males) were enrolled after PPCI. Only patients with left ventricular ejection fraction (LVEF) > 40%, as assessed by resting transthoracic echocardiography (TTE), were included. ETT with 12-lead ECG monitoring and right precordial leads, as also MPI were performed at 6 weeks, 6 months, and one year after intervention. Coronary angiography was performed at six months. RESULTS: Single-vessel disease was observed in 46.9% of the patients. The left anterior descending coronary artery was treated in 48.4% of the patients. Angiographic restenosis occurred in 28.8%. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of ETT in detecting restenosis were not significant. Right precordial leads did not add information. MPI sensitivity, specificity, PPV, NPV, and accuracy correlated with restenosis only in the 6-month follow-up, both when considering summed difference score >2 (p=0.006) and >4 (p=0.014). CONCLUSION: ETT did not discriminate restenosis in this population. MPI performed at 6 months correlated with restenosis and proved useful during follow-up.

The role of invasive therapies in elderly patients with acute myocardial infarction.

INTRODUCTION: In elderly patients with acute myocardial infarction, very little is known about the role of surgical myocardial revascularization and percutaneous coronary intervention (invasive therapies--IT), especially in the context of long-term outcomes after hospital discharge. METHODS: We analyzed 1588 patients with MI who had been included prospectively in a databank and followed for up to 7.5 years. In this population, 548 patients were >70 years old (elderly group--EG), and 1040 were <70 years of age (younger group--YG); 1088 underwent IT during hospitalization, and the remaining 500 were treated medically (conservative therapy--CT). Patients were monitored either by visit or by phone at least once a year. A standard questionnaire was administered to all patients. The impact of IT was analyzed with both non-adjusted and adjusted models. RESULTS: By the end of the follow-up period, the survival rates for the IT and CT groups were, respectively, 71.9% versus 47.2% in the global population (hazard ratio=0.55, P<0.001), 81.5% versus 66.6% in the YG (hazard ratio=0.68, P=0.018) and 48.8% versus 20.3% in the EG (hazard ratio=0.58, P<0.001). In the adjusted models, the hazard ratios were 0.62 (P<0.001) in the global population, 0.74 in the YG (P=0.073) and 0.64 (P=0.001) in the EG. CONCLUSION: Long-term follow-up of patients with myocardial infarction revealed that IT during the in-hospital phase was at least as effective in elderly patients as in younger patients.

Prognostic heterogeneity among patients with chronic stable coronary disease: determinants of long-term mortality after treatment with percutaneous intervention.

AIMS: To evaluate the risk and predictors of death in a large population of patients with stable coronary disease treated with percutaneous intervention. METHODS AND RESULTS: The study population comprised 1,276 patients with chronic angina or silent ischaemia who underwent elective coronary angioplasty. Baseline and in-hospital mortality data were prospectively collected for all patients during the index hospitalisation. Post-discharge outcome was assessed at out-patient clinic, by review of the patients' records, or direct phone contact. Deaths were classified as cardiac and non-cardiac. Age, peripheral arterial disease, congestive heart failure with NYHA class >or= III, triple-vessel disease, and procedural success (i.e. angiographic success for all lesions in the absence of peri-procedural infarction) remained as multivariate independent predictors of death. For the entire population 4-year cumulative all-cause and cardiac mortality were respectively 5.4% and 4.1%. Four-year mortality for patients without any multivariate predictor was 2.4%, while for patients with two or more predictors the death rate was 16.3% after four years. CONCLUSIONS: Patients with stable coronary disease undergoing percutaneous treatment have an overall low mortality rate after four years. Nevertheless, stable patients comprise a heterogeneous population in terms of risk profile, ranging from patients at very low risk of late death to individuals with a poor long-term prognosis.

Rationale and design for the PAINT randomized trial.

BACKGROUND: We describe the rationale and design for the 'PercutAneous INTervention with biodegradable-polymer based paclitaxel-eluting or sirolimus-eluting versus bare stents for de novo coronary lesions - PAINT trial'. OBJECTIVES: To evaluate two novel formulations of paclitaxel-eluting stent and the sirolimus-eluting stent against a stent with the same metallic structure but without polymer coating or drug elution. METHODS: The PAINT is a multicenter 3-arm randomized trial, conducted in Brazilian tertiary institutions, which included 275 patients allocated for the InfinniumR paclitaxel-eluting stent, the SupralimusR sirolimus-eluting stent or the Milennium MatrixR bare metal stent in a 2:2:1 ratio. Patients had de novo coronary lesions in native vessels with a diameter between 2.5 and 3.5 mm, amenable for treatment with a single stent of 29 mm or less in length. The primary objective was to compare the in-stent late loss at 9 months of both paclitaxel- and sirolimus-eluting versus the late loss of control bare metal stents. Important secondary objectives included the comparison in outcomes between sirolimus and paclitaxel stents, as well as the analysis of the incidence of major adverse cardiac events. RESULTS AND CONCLUSIONS: The PAINT trial had a unique design that allowed for the evaluation of the safety and efficacy profiles of two novel drug-eluting stent formulations, with a biodegradable-polymer carrier and releasing paclitaxel or sirolimus, which were compared against a bare metal stent (primary objective). As the drug-eluting stents differed by the drug, but were identical otherwise, the trial also allowed the comparison of the anti-restenosis effects of sirolimus versus paclitaxel (secondary objective).

A randomized trial of 5 versus 7 French guiding catheters for transfemoral percutaneous coronary stent implantation.

Comparative studies between 5 French guiding catheter and others of larger size using the transfemoral approach to coronary stenting have not been described. Coronary stent implantation was performed in 90 patients in a randomized trial. The primary end-point was to compare the incidence of successful uncomplicated stent implantation per lesion with the 5F and 7F guiding catheters. Patients were excluded for excessive vessel tortuosity or anticipated need for equipment not fitting through a 5 catheter. Baseline characteristics and the use of direct stenting did not differ between the two groups. The primary success rate was 97.8% per patient in both groups and 98% per lesion in the 5 French and 97.9% in the 7 French. Guiding catheter change was necessary in 1 patient in each group to successfully complete the procedure in both groups. The amount of contrast used was 63 +/- 27.3 mL in the 5 French and 76 +/- 25 mL in the 7 French groups (P < 0.05). Vascular complications and blood transfusions occurred somewhat more frequently in the 7 French group (P = 0.058). The manual compression time after sheath removal was 5.1 +/- 2.0 min and 8.0 +/- 4.3 min, respectively, in the 5 and 7 French groups (P < 0.01). In conclusion, the 5 French guiding catheters showed a similar success rate with coronary stenting when compared to the 7 French, but the amount of contrast used and manual compression time after sheath removal, as well as the rate of vascular and bleeding complications, were reduced in the 5 French group.

Enhanced inflammatory response following coronary stent implantation in stable angina patients.

BACKGROUND: Percutaneous coronary intervention (PCI) is associated with an increase in inflammatory activity. However, little is known about the association between the inflammatory response post-PCI and plaque morphology. The objective of this study was to characterize the inflammatory response following coronary stent implantation (CSI) of stable atherosclerotic plaques, according to plaque morphology. METHODS: The study population consisted of 62 patients with stable angina that had an elective indication of CSI. Immediately before CSI, the patients underwent intravascular ultrasound (IVUS) for determination of the predominant plaque morphology of the target lesion: calcified (C, n=15), fibrocalcified (FC, n=16), fibrolipidic (FL, n=16), or lipidic (L, n=15). Angiographic lesion types were also determined. Coronary sinus samples were collected at baseline (BL) and 15 min after CSI for measuring inflammatory mediators (IM): interleukin-6 (IL-6, in pg/ml), tumoral necrosis factor-alpha (TNF, in pg/ml), interferon-gamma (IFN, in IU/ml), and neopterin (N, in ng/ml). RESULTS: BL IL-6, TNF, IFN, and N were, respectively, for C plaques (mean+/-S.D.): 1.3+/-3.0, 8.0+/-3.5, 0.1+/-0.2, and 3.2+/-0.8; for FC plaques: 6.7+/-3.3, 1.9+/-2.0, 0.1+/-0.1, and 3.8+/-2.0; for FL plaques: 0.7+/-0.9, 8.7+/-4.3, 0.1+/-0.2, and 4.0+/-2.4; and, for L plaques: 1.9+/-2.8, 0.9+/-1.4, 0.0+/-0.1, and 5.2+/-3.3. After 15 min of CSI, percentual changes of IL-6, TNF, IFN, and N, respectively, were for C plaques: 43.8+/-19.6%, 7.7+/-5.5%, -7.5+/-5.3%, and -20.0+/-11.2%; for FC plaques: 7.7+/-5.5%, 168.4+/-56.9%, 311.1+/-159.9%, and 0%; for FL plaques: 147.5+/-16.1%*, 714.3+/-34.4%*, 116.1+/-9.9%*, and 3000.0+/-230.0%*; and, for L plaques: 147.7+/-14.4%*, 140.3+/-15.0%*, 131.6+/-11.9%*, and 2300.0+/-25.9%*. Moreover, B1 (n=28) and B2 (n=32) predominated and resulted in significant changes only for IL-6 and IFN, respectively. *P<0.05: 15 min vs BL. CONCLUSIONS: These data suggest that stable angina patients with predominant lipidic (L and FL) plaques present a greater inflammatory response after CSI in than those with predominant calcified (C and FC) plaques.

Angiographic segment size in patients referred for coronary intervention is influenced by constitutional, anatomical, and clinical features.

BACKGROUND: Factors influencing the size of target vessels of patients referred for coronary intervention are poorly defined. We aimed to investigate in a large series of patients undergoing percutaneous intervention the relation of constitutional, anatomical, and clinical features with the reference diameter of coronary vessels treated with stenting. METHODS: A total of 4,850 de novo coronary lesions, non-ostial and non-bifurcational, located in native vessels were analyzed. The following pre-specified characteristics were analyzed to reflect the relation between constitutional, anatomical, and clinical features on reference vessel diameter: age, gender, height, weight, proximal location, vessel, diabetes, hypertension, multivessel disease, and clinical presentation. RESULTS: The average reference diameter was 2.66+/-0.50 mm. All pre-specified markers had a significant relation with the vessel reference diameter at univariate analysis, except by hypertension which showed a strong tendency. However, at multivariate analysis, only diabetes, proximal location, multivessel disease, clinical presentation, vessel, weight, and height were identified as independent predictors of reference vessel diameter. CONCLUSION: Reference diameter of coronary vessels at the site of lesions treated by stenting is significantly influenced by a variety of characteristics. We hypothesize that the treated segment size of patients undergoing stenting ultimately reflects the conjoint effect of several different factors, including constitutional, anatomical, and clinical features.

Noninvasive evaluation of left circumflex coronary aneurysm by real-time three-dimensional echocardiography.

The diagnosis of coronary aneurysms has already been described using transthoracic and transesophageal echocardiography. In the present report we demonstrated the use of real-time three-dimensional echocardiography for the diagnosis of a large left circumflex coronary aneurysm. The improved spatial resolution of this new imaging technique provided valuable information for anatomic characterization of the coronary aneurysm, allowing for distinction between the lumen and lining thrombus. The findings were confirmed by magnetic resonance imaging and coronary angiography.

Early ambulation and variability in anticoagulation during elective coronary stenting with a single intravenous bolus of low-dose, low-molecular weight heparin enoxaparin.

BACKGROUND: The best anticoagulation strategy for patients undergoing percutaneous coronary intervention (PCI) remains controversial. The primary objective of this study was to assess the feasibility of immediate sheath removal post-PCI in patients given a single low-dose intravenous (IV) bolus of enoxaparin as the sole anticoagulant. METHODS: In 53 patients with stable coronary disease undergoing elective PCI, a single IV bolus of 0.5 mg per kg enoxaparin was administered 10 minutes before PCI. Patients were pretreated with aspirin 100 mg and clopidogrel 300 mg. The femoral access sheaths were removed immediately after PCI by manual compression. Major and minor bleeding and coronary thrombosis were recorded. Anti-Xa levels were measured before, during and after PCI. RESULTS: One patient had an intracoronary thrombus 60 minutes after enoxaparin administration, and there was 1 ischemic stroke. Fifty-one of the 53 patients had their sheaths successfully pulled immediately post-PCI. One patient had a pseudoaneurysm requiring surgical repair, and 1 patient had a minor bleed. Postprocedural elevation of CK-MB > 3 times the upper limit of normal occurred in 7 patients (13.2%). Anti-Xa activity was 0.56 +/- 0.16 at 10 minutes post-IV injection, and then progressively decreased to 0.14 +/- 0.09 IU/ml at 6 hours after injection. Ten minutes after IV enoxaparin, 12 patients (23.5%) had anti-Xa levels < 0.5 IU/ml. CONCLUSIONS: Immediate removal of femoral sheaths, after a single low-dose of IV enoxaparin for elective stenting appears feasible. However, a sizeable proportion of patients achieved anti-Xa levels below the widely agreed upon "therapeutic" level after injection.

Human myocardium preconditioning during successive balloon inflations: irrelevant influence of both collateral recruitment and clinical pre-intervention interference.

AIMS: We hypothesised that ischaemic preconditioning (IP) results from complex cellular mechanisms without significant collateral recruitment or clinical pre-intervention interference. METHODS AND RESULTS: A total of 58 patients underwent three 2-min balloon inflations separated by 5-min reperfusions. Anginal symptoms were graded according to this scale: 0 = absent, 1 = mild, 2 = moderate and 3 = severe. ST-segment shift and QT dispersion (QTd) were measured from 12 lead ECGs. Ejection fraction (EF) was assessed by 2D echo and collateral flow recruitment by collateral flow index (CFI). Anginal scores were 2.4+/-0.6, 1.7+/-0.5 and 1.2+/-0.6 (p<0.05); ST-segment shifts were 6.0+/-2.1, 3.8+/-1.8, and 1.9+/-1.2 mm (p<0.05); QTd increased from a baseline value of 39+/-24 to 96+/-27 (p<0.05) and decreased to 66+/-23 and 45+/-16 ms, at the end of the first, second and third inflation, respectively. EF decreased from a baseline value of 63+/-3% to 33+/-2%, 34+/-3%, and 36+/-5% in the three inflations. The CFI was approximately 0.15 in all ischaemic periods. CONCLUSION: These results suggest that IP does occur during repeated brief coronary artery occlusion in patients with a low likelihood of both collateral recruitment and clinical pre-intervention interference.

Myocardial perfusion scintigraphy to predict outcomes after coronary stenting.

The value of myocardial perfusion scintigraphy (MPS) in predicting the occurrence of restenosis or new coronary lesions after stent implantation is debatable. A total of 47 patients treated with successful bare stent implantation underwent stress gated SPECT MPS at three time-points: pre-procedure, early pos-procedure, and 6-month follow-up. Follow-up angiographic re-study was obtained at 6 months. Overall, 51.1% of patients had angiographic in-stent restenosis or a new lesion at follow-up. Pre-procedure MPS and early MPS scans did not differ between patients with or without restenosis/new lesions. At follow-up transient perfusion defects were observed in 26.1% of patients without restenosis/new lesions and in 75.0% of patients presenting with restenosis/new lesions (p<0.01) (sensitivity: 75.0%; especificity: 73.9%). When comparing early post procedure MPS to follow-up MPS, patients without restenosis/new lesions had no changes or a decrease in the number of segments with transient defects (median difference 0 [interquartile range -2 - 0]), while patients with restenosis/new lesions had an increase in transient defects (+2 [interquartile range 2 - 3.75]; p<0.01). Two multivariate factors independently predicted new lesion/restenosis: reference diameter < 2.9 mm (OR 6.50; p=0.05) and the difference in the number of segments with transient defects between early post procedure and follow-up MPS (OR 1.87; p<0.01). In conclusion, pre-procedure and early MPS did not predict complications after coronary stenting, while follow-up MPS was suboptimal in differentiating patients with or without new lesions/restenosis. However, the change in myocardial perfusion from early post-procedure to the follow-up scan was an important -prognostic factor to predict the incidence of new lesion/restenosis.

Late coronary artery recanalization effects on left ventricular remodelling and contractility by magnetic resonance imaging.

AIMS: To assess the recanalization effects of post-myocardial infarction (MI) on left ventricular (LV) remodelling and contractility in relation to conservative therapy. METHODS AND RESULTS: Thirty-six patients with occluded infarct-related artery between 12 h and 14 days post-anterior MI were randomized to percutaneous coronary intervention (PCI group) or conservative therapy (no-PCI group). Magnetic resonance imaging was performed at enrollment and after 6 months. The left ventricle was divided into infarct, adjacent, and remote segments. There was no difference in relation to LV volume between groups at the 6 month follow-up. Change in LV ejection fraction was favourable to the PCI group: 5.00% vs. -0.76%, P=0.012. Change in circumferential shortening (Ecc) of the remote segments in the PCI group was significantly better than in the no-PCI group: -1.67+/-6.30% vs. 0.29+/-6.02%, P<0.001. Infarct size and LV mass were similar between groups. CONCLUSIONS: Late recanalization improved LV ejection fraction and myocardial contractility in late follow-up, but did not change the ventricular volumes. Improvement in the left ventricle global and regional contractility may benefit the long-term outcome in post-MI patients with sustained patency of the infarct-related artery.

Avaliação não invasiva de pacientes submetidos à intervenção percutânea no infarto do miocárdio / Noninvasive assessment of patients undergoing percutaneous intervention in myocardial infarction

FUNDAMENTO: A reestenose pós-intervenção coronariana percutânea primária permanece um problema de relevância clínica, mesmo com o implante de stents. A capacidade das provas não invasivas para detecção de reestenose não foi totalmente demonstrada. OBJETIVO: Avaliar a habilidade do teste ergométrico (TE) e da cintilografia de perfusão miocárdica (CPM) no diagnóstico de reestenose em pacientes com infarto agudo do miocárdio, e supradenivelamento do segmento ST, submetidos à angioplastia coronariana percutânea primária (ACPP), com implante de stent nas primeiras 12 horas de evolução. MÉTODOS: De Ago/2003-Jan/2006, foram selecionados 64 pacientes (ps) (56,2 ± 10,2 anos, 53 homens) submetidos à ACPP. Apenas ps com fração de ejeção do ventrículo esquerdo > 40,0 por cento, definida por ecocardiograma de repouso, foram incluídos. Teste ergométrico, com as 12 derivações do ECG associadas a precordiais direitas, e CPM foram realizados 6 semanas, 6 meses e um ano após o tratamento. Foi realizada cinecoronariografia no 6º mês. RESULTADOS: Doença uniarterial ocorreu em 46,9 por cento dos ps, sendo a artéria descendente anterior tratada em 48,4 por cento. Reestenose angiográfica ocorreu em 28,8 por cento. Sensibilidade, especificidade, valor preditivo positivo (VPP), valor preditivo negativo (VPN) e acurácia do TE para detecção de reestenose não foram significativos. A adição de derivações precordiais direitas não proporcionou informações adicionais. Sensibilidade, especificidade, VPP, VPN e acurácia da CPM apresentaram correlação com reestenose apenas no 6º mês, considerando-se summed difference score > 2 (p = 0,006) e > 4 (p = 0,014). CONCLUSÃO: O TE não discriminou reestenose. A CPM realizada no 6º mês foi relacionada à reestenose e mostrou-se útil durante a evolução.

BACKGROUND: Restenosis after primary percutaneous coronary intervention (PPCI) remains an important clinical problem, even with stent implantation. The ability of noninvasive testing to diagnose restenosis has had only inconsistent demonstration. OBJECTIVE: Our objective was to evaluate the ability of exercise treadmill testing (ETT) and myocardial perfusion imaging (MPI) to diagnose restenosis in patients treated by PPCI within 12 hours of ST-elevation myocardial infarction (STEMI). METHODS: From August 2003 to January 2006, 64 patients (mean age of 56.2±10.2 years, 53 males) were enrolled after PPCI. Only patients with left ventricular ejection fraction (LVEF) > 40 percent, as assessed by resting transthoracic echocardiography (TTE), were included. ETT with 12-lead ECG monitoring and right precordial leads, as also MPI were performed at 6 weeks, 6 months, and one year after intervention. Coronary angiography was performed at six months. RESULTS: Single-vessel disease was observed in 46.9 percent of the patients. The left anterior descending coronary artery was treated in 48.4 percent of the patients. Angiographic restenosis occurred in 28.8 percent. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of ETT in detecting restenosis were not significant. Right precordial leads did not add information. MPI sensitivity, specificity, PPV, NPV, and accuracy correlated with restenosis only in the 6-month follow-up, both when considering summed difference score >2 (p=0.006) and >4 (p=0.014). CONCLUSION: ETT did not discriminate restenosis in this population. MPI performed at 6 months correlated with restenosis and proved useful during follow-up.

Resultados clínicos iniciais do primeiro stent de cromo-cobalto concebido no Brasil / Initial clinical results of the first cobalt-chromium stent designed in Brazil

FUNDAMENTOS: Os stents de cromo-cobalto são constituídos de hastes mais finas, apresentando maior flexibilidade e, possivelmente, menor proliferação neointimal que os stents de aço inoxidável. MÉTODO: O registro do stent Cronus (Scitech Produtos Médicos, Goiânia, GO) é um estudo prospectivo, não-randomizado, internacional, desenhado para avaliar a eficácia e a segurança do novo stent de cromo-cobalto de hastes finas em pacientes com insuficiência coronária. No total, 69 lesões foram tratadas em 53 pacientes envolvidos nessa análise. RESULTADOS: Foi constatado sucesso do dispositivo em 98,5% dos casos. A perda luminal tardia foi de 0,7 ± 0,5 mm, tendo ocorrido reestenose binária em 15% e revascularização do vasoalvo em 11,3% dos casos. A incidência de eventos cardíacos adversos maiores (morte, infarto do miocárdio ou revascularização do vaso-alvo) foi de 24,4% após 317 ± 80 dias de acompanhamento. CONCLUSÃO: Nossos resultados iniciais demonstram que o novo stent Cronus mostrou-se seguro e eficaz, com resultados clínicos semelhantes aos observados em outros stents de hastes finas.

BACKGROUND: Thin-strut cobalt-chromium stents have greater flexibility and probably have less neointimal proliferation than stainless steel stents. METHOD: The Cronus (Scitech Produtos Médicos, Goiânia, Brazil) registry is an international, non-randomized, prospective study designed to evaluate the efficacy and safety of a novel thin-strut cobalt-chromium stent in patients with coronary artery disease. A total of 69 lesions were treated in 53 patients included in this analysis. RESULTS: The device success was 98.5%. Mean late luminal loss was 0.7 ± 0.5 mm, binary restenosis occurred in 15% and target vessel revascularization in 11.3% of the cases. The incidence of major adverse cardiac events (death, myocardial infarction or target vessel revascularization) was 24.4% after 317 ± 80 days of follow-up. CONCLUSION: Our initial results demonstrate that the novel Cronus stent proved to be safe and effective, with clinical results similar to other available thin-strut stents.

Stenting vs. balloon angioplasty with provisional stenting for the treatment of vessels with small reference diameter.

A consecutive series of interventions in vessels with reference diameter < or = 2.75 mm was retrospectively analyzed according to preprocedure strategy: balloon angioplasty with provisional stenting (PTCA group, 73 patients) and primary stenting (PS group, 122 patients). In the PS group, there were more patients with single-vessel disease (54.1% vs. 37.0%; P = 0.021), less patients with three-vessel disease (9.0% vs. 24.7%; P = 0.003), more LAD interventions (54.9% vs. 31.5; P = 0.002), and less left circumflex interventions (22.1% vs. 45.2%; P < 0.001). Reference diameter was larger in the PS group (2.28 +/- 0.35 mm vs. 2.11 +/- 0.36 mm; P = 0.001). Provisional stenting was performed in 39.7% of PTCA group. At long-term outcome, the incidence of composite major events was similar between the PTCA and the PS groups (20.5% vs. 17.2%, respectively; P = NS). Treatment of small vessels with balloon dilatation and provisional stenting or with primary stenting yielded similar late outcomes. Operators' choice of treatment strategy was based on particular angiographic characteristics.