Additional value of dipyridamole stress myocardial perfusion by 64-row computed tomography in patients with coronary stents.

BACKGROUND: Coronary computed tomography angiography (CTA) is a well-established diagnostic tool for coronary artery disease (CAD). However, coronary segments with prior stent implantation visualized with CTA may have limited evaluation and reduced accuracy. OBJECTIVE: We assessed the incremental value of stress myocardial CT perfusion (CTP) over anatomical assessment by coronary CTA alone in patients with stents, using quantitative invasive coronary angiography (≥50%) as reference. METHODS: Forty-six patients (56.9 ± 7.2 years; 28 men) referred to invasive coronary angiography were evaluated, combining coronary CTA and dipyridamole stress myocardial CTP with 64 detector-row CT. Coronary CTA was evaluated for ≥50% coronary stenosis, and myocardial CTP was used to potentially reclassify coronary territories, including those with stents and poorly evaluated stents because of artifacts. RESULTS: We evaluated 138 coronary territories, 62 with ≥1 stent. From these, 21 (34%) territories had adequately evaluated stents, 28 (45%) had limitedly evaluated stents still allowing diagnosis, and 13 (21%) had inadequately evaluated stents (no luminal assessment possible). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy for coronary CTA in stent territories were, respectively, 85%, 77%, 87%, 74%, and 81%, and the combined use of coronary CTA and myocardial CTP were 88%, 95%, 97%, 81%, and 91% (P = 0.0292). In territories with impaired stent evaluation (limited or inadequate), the diagnostic performance of coronary CTA alone was 83%, 72%, 79%, 76% and 77%, and combined with myocardial CTP were 87%, 94%, 95%, 85%, and 91% (P = 0.036). CONCLUSION: The combined evaluation of coronary CTA and stress myocardial CTP improved the diagnostic accuracy for the detection of significant obstructive CAD in patients with stents.

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.

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.

Validation of a risk score for target vessel revascularization after coronary stent implantation.

OBJECTIVE: Our aim was to validate a risk score for new target vessel revascularization (TVR) after bare-metal stent (BMS) implantation. METHODS: The risk score was developed in a cohort of patients previously treated with BMS at our institution. This risk score ranges from 0 to 5 points, according to the presence of diabetes mellitus (1 point), reference vessel diameter (> 3.5 mm = 0 points; 3-3.5 mm = 1; < 3 mm = 2) and lesion length (< or = 10 mm = 0 points; 10-20 mm = 1; > 20 mm = 2). Patients included in the validation cohort were treated between January and December 2005. Patient characteristics and 1-year clinical follow up were prospectively recorded into a dedicated database. A new coronary angiography was performed only when recurrent ischemia was suspected. RESULTS: The mean age of the 491 patients included was 61 +/- 10.5 years, and 35% were women. Diabetes mellitus was present in 22%, a previous percutaneous coronary intervention in 12% and previous myocardial infarction in 35%. The mean reference vessel diameter was 2.80 +/- 0.56 mm and the mean lesion length was 12.45 +/- 6.3 mm. The overall 1-year TVR rate was 13.9%. TVR rates increased with each score level: Score = 0, TVR = 0% (n = 16); Score 1 = 5.3% (n = 48); Score 2 = 12% (n = 170); Score 3 = 14% (n = 146); and Score 4/5 = 25% (n = 54); (p = 0.008). CONCLUSIONS: The risk score was significantly associated with TVR rates and can be used as a simple clinical tool to identify those patients at a low risk for a new revascularization procedure.

Teste ergométrico após intervenção coronária percutânea e cirurgia de revascularização miocárdica / Stress testing after percutaneous coronary intervention and coronary artery bypass graft

No acompanhamento dos pacientes submetidos a revascularização do miocárdio por cirurgia ou intervenção coronária percutânea, algumas das preocupações são a oclusão das pontes, a presença de reestenose ou a progressão da doença, principalmente em pacientes assintomáticos. Desse modo, torna-se necessária a utilização de exames para detecção precoce desses eventos. O teste ergométrico é um dos métodos não-invasivos utilizados para esse fim, sendo fácil, seguro e, principalmente, de menor custo quando comparado aos métodos de imagem. Entretanto, quando estudado em grupos selecionados, como em pacientes com apenas um vaso doente e com eletrocardiograma de repouso sem alterações, o uso do teste ergométrico mostrou bons resultados. Além disso, alguns parâmetros do teste ergométrico têm valor significativo para avaliação de pacientes revascularizados ou após intervenção coronária percutânea. Mais especificamente, foi demonstrado que o tempo de duração do exercício é capaz de predizer a presença ou não de reestenose e/ou novas lesões. O teste ergométrico em indivíduos submetidos a intervenção coronária...

Coronary stenting and inflammation: implications for further surgical and medical treatment.

The introduction of percutaneous coronary interventions (PCI) with stent implant has substantially shifted the treatment of coronary artery disease. The current approach to coronary artery disease treatment includes first-choice PCI in selected subgroups; and once this therapy fails, frequently the patient is referred for coronary artery bypass graft surgery. However, evidence of chronic inflammatory reaction and endothelial dysfunction after PCI has been emerging and that might be interfering with patient outcome when surgical or medical treatments are subsequently required. The clinical significance of these complications after PCI, herein examined, has been less studied and needs better assessment. Also, the premise that coronary artery bypass graft surgery can safely be performed in patients with coronary stenting failure may not hold true, as graft patency might be adversely affected. Furthermore, the superimposed inflammatory reaction may blunt the efficacy of medical treatment.

[Coronary physiology and its usefulness for the interventionist cardiologist: invasive measurement of coronary flow-pressure]. / Fisiología coronaria y su utilidad para el cardiólogo intervencionista: medición invasiva de la presión y flujo coronarios.

One of the most important limitations of coronary angiography is the inability to characterize the physiological significance of an intermediate coronary stenosis. Measuring coronary blood flow and pressure provides unique information that complements anatomic evaluation and facilitates decision-making in the cardiac catheterization unit. This review discusses the fundamental concepts of coronary physiology, methodology, and clinical applications of coronary and flow measurements.

Fisiología coronaria y su utilidad para el cardiólogo intervencionista: Medición invasiva de la presión y flujo coronarios / Coronary physiology and its usefulness for the interventionist cardiologist: Invasive measurement of coronary flow-pressure

Una de las más importantes limitaciones de la angiografía coronaria es su incapacidad para determinar el impacto fisiológico de las estenosis coronarias moderadas. La medición de la presión y del flujo sanguíneo coronario nos brinda información valiosa que complementa la evaluación anatómica y facilitan la toma de decisiones en el laboratorio de cateterismo cardíaco. En esta revisión se discuten los conceptos fundamentales de la fisiología coronaria, así como la metodología y aplicación clínica de las técnicas de medición de presión y flujo coronarios.

One of the most important limitations of coronary angiography is the inability to characterize the physiological significance of an intermediate coronary stenosis. Measuring coronary blood flow and pressure provides unique information that complements anatomic evaluation and facilitates decision-making in the cardiac catheterization unit. This review discusses the fundamental concepts of coronary physiology, methodology, and clinical applications of coronary and flow measurements.

Coronary blood flow reserve response to left anterior descending coronary artery stenting and its value in predicting coronary restenosis.

BACKGROUND: Heterogeneous results of coronary flow velocity reserve (CFVR) to percutaneous procedures have been reported and the impact of transesophageal echocardiographic evaluation of CFVR in predicting restenosis has not been completely established. METHODS AND RESULTS: We studied 20 control volunteers and 51 patients with left anterior descending coronary artery stenosis to determine the CFVR response to left anterior descending coronary artery stenting, the clinical markers of persistent CFVR impairment, and its value in predicting restenosis. Prestent CFVR was lower in the stenosis group than in control volunteers (1.89 +/- 0.66 vs 3.82 +/- 1.15; P <.001). Although there was a significant increase of CFVR after stenting (2.58 +/- 0.76; P <.001 vs prestent), it remained depressed in 53% of patients and was independently related to multivessel disease (odds ratio, 0.14; 95% confidence interval 0.03-0.55; P =.005), age (odds ratio, 1.07; 95% confidence interval 0.99-1.15; P =.056), and prestent CFVR (odds ratio, 3.78; 95% confidence interval 0.99-14.42; P =.051). CFVR measured both before and early after stenting did not differ between patients with and without restenosis. CONCLUSIONS: CFVR impairment occurs in a large proportion of patients despite successful stenting and appears to be consequent of the extent of atherosclerotic coronary disease. Periprocedural CFVR conferred no predictive value for subsequent intrastent restenosis.

Multicenter randomized comparison of direct vs. conventional stenting: the DIRECTO trial.

With conventional stenting, predilatation frequently induces dissections that require deploying stents longer than originally planned. To assess whether direct stenting is safe and may prevent dissections and reduce the length of stents implanted, we conducted a randomized study comparing direct (n = 73) and conventional (n = 78) stenting. Direct stenting was successful in 89% of cases, 11% crossed over to predilation without complications. Dissections occurred more frequently in conventional stenting group (10.3% vs. 1.4%; P = 0.034), but did not translate to a significant stent length difference (16.31 +/- 7.6 vs. 15.31 +/- 5.5; P = NS). Periprocedure creatine kinase elevation and number of balloons utilized were lower with direct stenting.

What is "the matter" with restenosis in 2002?

Undoubtedly, we have come a long way since the introduction of intracoronary stents, but restenosis continue to plague cardiologists. Much research has been devoted to pathophysiology and treatment of in-stent restenosis, and it is possible that we never will. The detailed pathological investigation by farb et al published in this issue of Circulation elegantly portrays a putative novel mechanism related to the initiation os restenosis.