The Prognostic Value and Clinical Use of Myocardial Perfusion Scintigraphy in Asymptomatic Patients after Percutaneous Coronary Intervention.

BACKGROUND: The role of myocardial perfusion scintigraphy (MPS) in the follow-up of asymptomatic patients after percutaneous coronary intervention (PCI) is not established. OBJECTIVES: To evaluate the prognostic value and clinical use of MPS in asymptomatic patients after PCI. METHODS: Patients who underwent MPS consecutively between 2008 and 2012 after PCI were selected. The MPS were classified as normal and abnormal, the perfusion scores, summed stress score (SSS), and summed difference score (SDS) were calculated and converted into percentage of total perfusion defect and ischemic defect. The follow-up was undertaken through telephone interviews and consultation with the Mortality Information System. Primary endpoints were death, cardiovascular death, and nonfatal acute myocardial infarction (AMI), and secondary endpoint was revascularization. Logistic regression and COX method were used to identify the predictors of events, and the value of p < 0.05 was considered statistically significant. RESULTS: A total of 647 patients were followed for 5.2 ± 1.6 years. 47% of MPS were normal, 30% were abnormal with ischemia, and 23% were abnormal without ischemia. There were 61 deaths, 27 being cardiovascular, 19 non-fatal AMI, and 139 revascularizations. The annual death rate was higher in those with abnormal perfusion without ischemia compared to the groups with ischemia and normal perfusion (3.3% × 2% × 1.2%, p = 0.021). The annual revascularization rate was 10.3% in the ischemia group, 3.7% in those with normal MPS, and 3% in those with abnormal MPS without ischemia. The independent predictors of mortality and revascularization were, respectively, total perfusion defect greater than 6%, and ischemic defect greater than 3%. Forty-two percent of the patients underwent MPS less than 2 years after PCI, and no significant differences were observed in relation to those who underwent it after that period. CONCLUSION: Although this information is not contemplated in guidelines, in this study MPS was able to predict events in asymptomatic after PCI patients, regardless of when they were performed.

Prognostic performance of coronary computed tomography angiography in asymptomatic individuals as compared to symptomatic patients with an appropriate indication.

INTRODUCTION: Current Appropriatene Usa Criteria exclude coronary computed tomography angiography (CTA) in asymptomatic individuals. We compared the prognostic value of coronary CTA in asymptomatic individuals to symptomatic patients with "definitely appropriate" indications for coronary CTA. METHODS: Consecutive patients without previously known CAD referred for a CTA exam were divided into 2 groups. One group consisted ofasymptomatic individuals, the other of symptomatic patients with a "definitely appropriate" indication for coronary CT (unable to exercise and/or with an uninterpretable electrocardiogram and at an intermediate pre-test probability of obstructive coronary artery disease). Patients that did not fit into either groups were excluded. The segment stenosis score (SSS) was calculated based on coronary CTA and patients were followed for a composite endpoint of all-cause death, acute myocardial infarction and late revascularization. RESULTS: A total of 1080 patients (60 ± 12 years, 65% male) were included in the study (674 "asymptomatic" and 406 "appropriate"). SSS >4 was more frequent in "asymptomatic" than in "appropriate" CT data sets (27% vs 20%, p = 0.02). After a mean follow-up of 4.4 ± 1.8 yrs, 49 patients reached the composite endpoint. On multivariable analysis adjusting for CAD risk factors and symptoms, only a high-risk CTA study and past smoking were independently predictive of events. CONCLUSIONS: Although currently not regarded as "definitely appropriate", the use of coronary CTA in a selected asymptomatic population had higher yield for identifying high-risk individuals than appropriately indicated studies in symptomatic patients and provided thequal prognostic information.

Factors Associated With Coronary Artery Disease Progression Assessed By Serial Coronary Computed Tomography Angiography.

Background: Coronary computed tomography angiography (CCTA) allows for noninvasive coronary artery disease (CAD) phenotyping. Factors related to CAD progression are epidemiologically valuable. Objective: To identify factors associated with CAD progression in patients undergoing sequential CCTA testing. Methods: We retrospectively analyzed 384 consecutive patients who had at least two CCTA studies between December 2005 and March 2013. Due to limitations in the quantification of CAD progression, we excluded patients who had undergone surgical revascularization previously or percutaneous coronary intervention (PCI) between studies. CAD progression was defined as any increase in the adapted segment stenosis score (calculated using the number of diseased segments and stenosis severity) in all coronary segments without stent (in-stent restenosis was excluded from the analysis). Stepwise logistic regression was used to assess variables associated with CAD progression. Results: From a final population of 234 patients, a total of 117 (50%) had CAD progression. In a model accounting for major CAD risk factors and other baseline characteristics, only age (odds ratio [OR] 1.04, 95% confidence interval [95%CI] 1.01-1.07), interstudy interval (OR 1.03, 95%CI 1.01-1.04), and past PCI (OR 3.66, 95%CI 1.77-7.55) showed an independent relationship with CAD progression. Conclusions: A history of PCI with stent placement was independently associated with a 3.7-fold increase in the odds of CAD progression, excluding in-stent restenosis. Age and interstudy interval were also independent predictors of progression.

Objetivo: Angiografia coronariana por tomografia computadorizada (ACTC) permite fenotipagem não invasiva da doença arterial coronariana (DAC). Fatores relacionados à progressão da DAC têm valor epidemiológico. Métodos: Nós analisamos retrospectivamente 384 pacientes consecutivos que apresentavam pelo menos duas avaliações por ACTC entre dezembro de 2005 e março de 2013. Devido às limitações na quantificação da progressão da DAC, os pacientes que haviam sido submetidos previamente à revascularização cirúrgica ou intervenção coronariana percutânea (ICP) entre as avaliações foram excluídos. A progressão da DAC foi definida como qualquer aumento no escore adaptado de estenose segmentar (calculado com utilização do número de segmentos afetados e gravidade da estenose) em todos os segmentos coronarianos sem stent (restenose intra-stent foi excluída da análise). Regressão logística stepwise foi utilizada para avaliar as variáveis associadas com a progressão da DAC. Resultados: De uma população final de 234 pacientes, um total de 117 (50%) pacientes apresentaram progressão da DAC. Em um modelo considerando os principais fatores de risco para DAC e outras características basais, apenas a idade (odds ratio [OR] 1,04, intervalo de confiança de 95% [IC95%] 1,01-1,07), intervalo entre avaliações (OR 1,03, IC95% 1,01-1,04) e ICP prévia (OR 3,66, IC95% 1,77-7,55) mostraram uma relação independente com a progressão da DAC. Conclusões: Uma história de ICP com implante de stent esteve independentemente associada a um aumento de 3,7 vezes na chance de progressão da DAC, excluindo a restenose intra-stent. Idade e intervalo entre avaliações também foram preditores independentes de progressão.

Changes in Medical Management after Coronary CT Angiography.

INTRODUCTION: Coronary computed tomography angiography (CCTA) allows for non-invasive coronary artery disease (CAD) phenotyping. There are still some uncertainties regarding the impact this knowledge has on the clinical care of patients. OBJECTIVE: To determine whether CAD phenotyping by CCTA influences clinical decision making by the prescription of cardiovascular drugs and their impact on non-LDL cholesterol (NLDLC) levels. METHODS: We analysed consecutive patients from 2008 to 2011 submitted to CCTA without previous diagnosis of CAD that had two serial measures of NLDLC, one up to 3 months before CCTA and the second from 3 to 6 months after. RESULTS: A total of 97 patients were included, of which 69% were men, mean age 64 ± 12 years. CCTA revealed that 18 (18%) patients had no CAD, 38 (39%) had non-obstructive (< 50%) lesions and 41 (42%) had at least one obstructive ≥ 50% lesion. NLDLC was similar at baseline between the grups (138 ± 52 mg/dL vs. 135 ± 42 mg/dL vs. 131 ± 44 mg/dL, respectively, p = 0.32). We found significative reduction in NLDLC among patients with obstrctive lesions (-18%, p = 0.001). We also found a positive relationship between clinical treatment intensification with aspirin and cholesterol reducing drugs and the severity of CAD. CONCLUSION: Our data suggest that CCTA results were used for cardiovascular clinical treatment titration, with especial intensification seen in patients with obstructive ≥50% CAD.

The Prognostic Value and Clinical Use of Myocardial Perfusion Scintigraphy in Asymptomatic Patients after Percutaneous Coronary Intervention / O Valor Prognóstico e o uso Clínico da Cintilografia de Perfusão Miocárdica em Pacientes Assintomáticos após Intervenção Coronariana Percutânea

Abstract Background: The role of myocardial perfusion scintigraphy (MPS) in the follow-up of asymptomatic patients after percutaneous coronary intervention (PCI) is not established. Objectives: To evaluate the prognostic value and clinical use of MPS in asymptomatic patients after PCI. Methods: Patients who underwent MPS consecutively between 2008 and 2012 after PCI were selected. The MPS were classified as normal and abnormal, the perfusion scores, summed stress score (SSS), and summed difference score (SDS) were calculated and converted into percentage of total perfusion defect and ischemic defect. The follow-up was undertaken through telephone interviews and consultation with the Mortality Information System. Primary endpoints were death, cardiovascular death, and nonfatal acute myocardial infarction (AMI), and secondary endpoint was revascularization. Logistic regression and COX method were used to identify the predictors of events, and the value of p < 0.05 was considered statistically significant. Results: A total of 647 patients were followed for 5.2 ± 1.6 years. 47% of MPS were normal, 30% were abnormal with ischemia, and 23% were abnormal without ischemia. There were 61 deaths, 27 being cardiovascular, 19 non-fatal AMI, and 139 revascularizations. The annual death rate was higher in those with abnormal perfusion without ischemia compared to the groups with ischemia and normal perfusion (3.3% × 2% × 1.2%, p = 0.021). The annual revascularization rate was 10.3% in the ischemia group, 3.7% in those with normal MPS, and 3% in those with abnormal MPS without ischemia. The independent predictors of mortality and revascularization were, respectively, total perfusion defect greater than 6%, and ischemic defect greater than 3%. Forty-two percent of the patients underwent MPS less than 2 years after PCI, and no significant differences were observed in relation to those who underwent it after that period. Conclusion: Although this information is not contemplated in guidelines, in this study MPS was able to predict events in asymptomatic after PCI patients, regardless of when they were performed.

Resumo Fundamentos: O papel da cintilografia de perfusão miocárdica (CPM) no seguimento de pacientes assintomáticos após intervenção coronariana percutânea (ICP) não está estabelecido. Objetivos. Avaliar o valor prognóstico e o uso clínico da CPM em pacientes assintomáticos após ICP. Métodos: Foram selecionados pacientes que realizaram CPM consecutivamente entre 2008 e 2012 após ICP. As CPM foram classificadas em normais e anormais, os escores de perfusão, escore somado do estresse (SSS) e escore somado da diferença (SDS) foram calculados e convertidos em porcentagem de defeito perfusional total e de defeito isquêmico. O seguimento foi por meio de entrevistas telefônicas e consulta ao Sistema de Informação de Mortalidade. Desfechos primários foram morte, morte cardiovascular e infarto agudo do miocárdio (IAM) não fatal e desfecho secundário foi revascularização. Regressão logística e método de COX foram utilizados para identificar os preditores de eventos e o valor de p < 0,05 foi considerado estatisticamente significativo. Resultados: 647 pacientes foram acompanhados por 5,2 ± 1,6 anos. 47% das CPM foram normais, 30% anormais com isquemia e 23% anormais sem isquemia. Ocorreram 61 mortes, 27 cardiovasculares, 19 IAM não fatais e 139 revascularizações. A taxa anual de óbitos foi superior naqueles com perfusão anormal sem isquemia comparada aos grupos com isquemia e perfusão normal (3,3% × 2% × 1,2%, p = 0,021). A taxa anual de revascularização foi 10,3% no grupo com isquemia, 3,7% naqueles com CPM normal e 3% naqueles com CPM anormal sem isquemia. Foram preditores independentes de mortalidade e revascularização, respectivamente, defeito perfusional total maior que 6% e defeito isquêmico maior que 3%. Quarenta e dois por cento dos pacientes realizaram CPM menos de 2 anos após ICP e não foram observadas diferenças relevantes em relação aos que realizaram após esse período. Conclusão: Embora esta informação não esteja contemplada em diretrizes, neste estudo a CPM foi capaz de predizer eventos em pacientes assintomáticos após ICP, independente do momento de realização.

Preditores da indicação de coronariografia pós-cintilografia miocárdica de perfusão / Predictors for indication to catheterization after myocardial perfusion gated spec

Fundamentos: Pacientes coronariopatas portadores de disfunção ventricular esquerda apresentam maior mortalidade e por isso são os maiores beneficiados de procedimento de revascularização miocárdica. Estudo anterior demonstrou que a fração de ejeção do ventrículo esquerdo (FEVE) é um determinante negativo para realização de cateterismo cardíaco (CAT) após a realização de cintilografia miocárdica de perfusão (CMP). Objetivo: Determinar os fatores clínicos e cintilográficos associados à indicação de cateterismo cardíaco em pacientes submetidos a CMP. População: Pacientes consecutivamente submetidos a CMP no período de março de 2008 a dezembro de 2012. Metodologia: Todos os pacientes submetidos a CMP durante o estudo foram cadastrados num banco de dados, onde foram registrados os dados epidemiológicos, clínicos e cintilográficos (escores de perfusão e FEVE). Pacientes ou seus médicos assistentes foram contatados semestralmente por telefone para acompanhamento. Para análise estatística, foram realizadas análise univariada e selecionadas as variáveis para a inclusão em um modelo de regressão logística. Resultados: Foram submetidos a CMP 5536 pacientes, dos quais 643 realizaram CAT após o exame. Este grupo apresenta maior prevalência do sexo masculino, hipertensos, dislipidêmicos e revascularizados previamente. Os pacientes submetidos ao CAT têm angina com mais frequência, escores de isquemia mais extensos e menor FEVE. Apenas a presença de angina (IC 95% 1,2 - 1,7; p < 0,001) e a extensão de isquemia (IC 95% 1,2 - 1,3; p < 0,001) se mostraram variáveis independentes para indicação de CAT. Conclusão: A presença de angina e a extensão de isquemia foram os principais preditores para indicação de CAT pós-CMP enquanto a FEVE menor não foi um preditor independente

Background: Patients with coronary artery disease with left ventricular dysfunction present higher mortality and are the major beneficiaries of a myocardial revascularization procedure. A previous study showed that left ventricular ejection fraction (LVEF) is a negative determinant for cardiac catheterization (CAT) after myocardial perfusion scintigraphy (MPS). Objective: To determine clinical and scintigraphic factors associated with cardiac catheterization (CAT) indication in patients undergoing myocardial perfusion SPECT (MPS).Population: Patients consecutively submitted to PMC in the period from March 2008 to December 2012. Methods: All patients undergoing MPS during the study were recorded in a data bank, where epidemiological, clinical and scintigraphic data (perfusion scores and LVEF) were recorded. Patients or their attending physicians were contacted by phone semiannually for follow-up. For statistical analysis, univariate analyzes were performed and variables were selected for inclusion in a logistic regression model. Results: 5536 patients were submitted to MPS, of which 643 performed CAT after the examination. This group presents a higher prevalence of males, hypertensive, dyslipidemic and previously revascularized. Patients undergoing CAT have angina more frequently, more extensive ischemia scores and lower LVEF. Only presence of angina (IC95% 1.2 - 1.7, p < 0.001) and extent of ischemia (95% CI 1.2 - 1.3, p < 0.001) were independent variables for CAT indication. Conclusion: The presence of angina and the extent of ischemia were the main predictors for CAT post-MPS indication while lower LVEF was not an independent predictor

Factors Associated With Coronary Artery Disease Progression Assessed By Serial Coronary Computed Tomography Angiography / Fatores Associados com Progressão da Doença Arterial Coronariana Avaliada por Angiografia Coronariana por Tomografia Computadorizada Seriada

Abstract Background: Coronary computed tomography angiography (CCTA) allows for noninvasive coronary artery disease (CAD) phenotyping. Factors related to CAD progression are epidemiologically valuable. Objective: To identify factors associated with CAD progression in patients undergoing sequential CCTA testing. Methods: We retrospectively analyzed 384 consecutive patients who had at least two CCTA studies between December 2005 and March 2013. Due to limitations in the quantification of CAD progression, we excluded patients who had undergone surgical revascularization previously or percutaneous coronary intervention (PCI) between studies. CAD progression was defined as any increase in the adapted segment stenosis score (calculated using the number of diseased segments and stenosis severity) in all coronary segments without stent (in-stent restenosis was excluded from the analysis). Stepwise logistic regression was used to assess variables associated with CAD progression. Results: From a final population of 234 patients, a total of 117 (50%) had CAD progression. In a model accounting for major CAD risk factors and other baseline characteristics, only age (odds ratio [OR] 1.04, 95% confidence interval [95%CI] 1.01-1.07), interstudy interval (OR 1.03, 95%CI 1.01-1.04), and past PCI (OR 3.66, 95%CI 1.77-7.55) showed an independent relationship with CAD progression. Conclusions: A history of PCI with stent placement was independently associated with a 3.7-fold increase in the odds of CAD progression, excluding in-stent restenosis. Age and interstudy interval were also independent predictors of progression.

Resumo Fundamento: Angiografia coronariana por tomografia computadorizada (ACTC) permite fenotipagem não invasiva da doença arterial coronariana (DAC). Fatores relacionados à progressão da DAC têm valor epidemiológico. Objetivo: Identificar os fatores associados com a progressão da DAC em pacientes submetidos à avaliação sequencial por ACTC. Métodos: Nós analisamos retrospectivamente 384 pacientes consecutivos que apresentavam pelo menos duas avaliações por ACTC entre dezembro de 2005 e março de 2013. Devido às limitações na quantificação da progressão da DAC, os pacientes que haviam sido submetidos previamente à revascularização cirúrgica ou intervenção coronariana percutânea (ICP) entre as avaliações foram excluídos. A progressão da DAC foi definida como qualquer aumento no escore adaptado de estenose segmentar (calculado com utilização do número de segmentos afetados e gravidade da estenose) em todos os segmentos coronarianos sem stent (restenose intra-stent foi excluída da análise). Regressão logística stepwise foi utilizada para avaliar as variáveis associadas com a progressão da DAC. Resultados: De uma população final de 234 pacientes, um total de 117 (50%) pacientes apresentaram progressão da DAC. Em um modelo considerando os principais fatores de risco para DAC e outras características basais, apenas a idade (odds ratio [OR] 1,04, intervalo de confiança de 95% [IC95%] 1,01-1,07), intervalo entre avaliações (OR 1,03, IC95% 1,01-1,04) e ICP prévia (OR 3,66, IC95% 1,77-7,55) mostraram uma relação independente com a progressão da DAC. Conclusões: Uma história de ICP com implante de stent esteve independentemente associada a um aumento de 3,7 vezes na chance de progressão da DAC, excluindo a restenose intra-stent. Idade e intervalo entre avaliações também foram preditores independentes de progressão.

Changes in Medical Management after Coronary CT Angiography / Mudanças no Manejo Clínico após Angiotomografia Coronariana

AbstractIntroduction:Coronary computed tomography angiography (CCTA) allows for non-invasive coronary artery disease (CAD) phenotyping. There are still some uncertainties regarding the impact this knowledge has on the clinical care of patients.Objective:To determine whether CAD phenotyping by CCTA influences clinical decision making by the prescription of cardiovascular drugs and their impact on non-LDL cholesterol (NLDLC) levels.Methods:We analysed consecutive patients from 2008 to 2011 submitted to CCTA without previous diagnosis of CAD that had two serial measures of NLDLC, one up to 3 months before CCTA and the second from 3 to 6 months after.Results:A total of 97 patients were included, of which 69% were men, mean age 64 ± 12 years. CCTA revealed that 18 (18%) patients had no CAD, 38 (39%) had non-obstructive (< 50%) lesions and 41 (42%) had at least one obstructive ≥ 50% lesion. NLDLC was similar at baseline between the grups (138 ± 52 mg/dL vs. 135 ± 42 mg/dL vs. 131 ± 44 mg/dL, respectively, p = 0.32). We found significative reduction in NLDLC among patients with obstrctive lesions (-18%, p = 0.001). We also found a positive relationship between clinical treatment intensification with aspirin and cholesterol reducing drugs and the severity of CAD.Conclusion:Our data suggest that CCTA results were used for cardiovascular clinical treatment titration, with especial intensification seen in patients with obstructive ≥50% CAD.

ResumoFundamento:A Angiotomografia Coronariana (AngioTC Cor) permite a fenotipagem de Doença Arterial Coronariana (DAC) de forma não invasiva. Ainda há incertezas sobre o impacto que esse conhecimento promove no tratamento clínico do paciente.Objetivo:Avaliar se a fenotipagem da DAC por AngioTC Cor influencia na tomada de decisão sobre o início da terapêutica cardiovascular e seu impacto nos níveis séricos de colesterol não HDL (CNHDL).Métodos:Foram analisados pacientes consecutivos sem diagnóstico prévio de DAC que realizaram AngioTC Cor entre os anos 2008 e 2011 e que possuíam duas dosagens seriadas de colesterol até três meses antes da AngioTC Cor, e de três a seis meses após.Resultados:Um total de 97 pacientes foram incluídos, sendo 69% homens, idade média de 64 ± 12 anos. A AngioTC Cor revelou que 18 (18%) pacientes não tinham lesões detectáveis, 38 (39%) tinham lesões não obstrutivas < 50%, e 41 (42%) tinham ao menos uma lesão obstrutiva ≥ 50%. As medidas de CNHDL basal foram similares entre os grupos, (138 ± 52 mg/dL vs. 135 ± 42 mg/dL vs. 131 ± 44 mg/dL, respectivamente, p = 0,32). Observou-se redução significativa do CNHDL apenas no grupo com lesões obstrutivas ≥ 50% (-18%, p = 0,001). Observa-se ainda relação entre a intensificação do tratamento clínico com AAS e drogas redutoras de colesterol proporcional à gravidade da DAC pela AngioTC Cor.Conclusão:Esses dados sugerem que o resultado da AngioTC Cor foi utilizado para a titulação terapêutica de pacientes com DAC, sendo o tratamento intensificado especialmente em DAC obstrutiva ≥ 50%.

Resistência ao AAS na doença coronariana estável / Aspirin resistance in stable coronary disease

Fundamentos: A doença arterial coronariana (DAC) apresenta alta morbimortalidade. A angioplastia coronariana e antiagregação com ácido acetilsalicílico (AAS) são fundamentais no tratamento desses pacientes. No contexto da angioplastia eletiva, carece estudos referentes aos fatores associados à resistência ao AAS.Objetivo: Avaliar a prevalência e os fatores relacionados à resistência ao AAS em pacientes submetidos àangioplastia eletiva. Métodos: Coorte retrospectiva de 198 pacientes submetidos à angioplastia eletiva, avaliados quanto à resistência ao AAS pela agregometria óptica com ácido araquidônico como agonista.Resultados: Observou-se resistência ao AAS em 6,56% da coorte (13/198). Os níveis de proteína C-reativa (PCR-t)mostraram associação com a resistência ao AAS (p=0,02). Conclusões: A prevalência da resistência ao AAS observada nos pacientes submetidos à angioplastia eletiva é baixa e os níveis elevados de proteína C-reativa relacionaram-se com maior chance de ocorrência dessa resistência.

Background: Coronary artery disease (CAD) has high morbidity and mortality rates. Coronary angioplasty and antiplatelet therapy with acetylsalicylic acid (ASA) are critical in treating CAD patients. Elective angioplasty lacks studies on the factors associatedwith resistance to ASA. Objective: To evaluate the prevalence and ASA resistance related factors in patients undergoing elective angioplasty.Methods: Retrospective cohort study of 198 patients undergoing elective angioplasty, evaluated for resistance to ASA by optical aggregometry with arachidonic acid as agonist. Results: Resistance to ASA in 6.56% of the cohort (13/198). C-reactive protein (CRP) levels indicated association with resistance to ASA (p=0.02).Conclusions: Low prevalence of ASA resistance in patients undergoing elective angioplasty; C-reactive protein high levels are related to greater frequency of this resistance.

Influência da fístula arteriovenosa sobre a resposta da frequência cardíaca ao dipiridamol em pacientes renais crônicos submetidos à cintilografia miocárdica / Influence of arteriovenous fistula on the heart rate response to dipyridamole in chronic renal patients undergoing

Fundamentos: Uma resposta diminuída da frequência cardíaca (FC) ao dipiridamol ocorre nos portadores de doença renal crônica (DRC) por razões não elucidadas. Após ampla revisão da literatura, não se encontraram estudos sobre a contribuição da fístula arteriovenosa (FAV) para esse fenômeno. Objetivo: Avaliar o papel da FAV para a resposta diminuída da FC ao dipiridamol em renais crônicos submetidos à cintilografia miocárdica. Métodos: Estudados 516 pacientes adultos, sendo 45 renais crônicos (25 com FAV e 20 sem FAV) e 471 comfunção renal normal, submetidos à cintilografia miocárdica em hospital terciário, entre 2006 e 2009. Todos os pacientes foram avaliados quanto à resposta hemodinâmica ao dipiridamol e a alguns parâmetros clínicos e cintilográficos. A resposta anormal da FC ao dipiridamol foi definida como razão FC pico/FC basal≤1,2 e diferença FC pico-Fc basal<12bpm. Resultados: A resposta diminuída da FC ao dipiridamol ocorreu de forma equivalente em ambos os grupos de renais crônicos, com ou sem FAV, e mais frequente do que no grupo de não DRC (68% vs. 70% vs. 29,7%, p<0,001, respectivamente). Pela regressão logística, determinou-se como preditores de resposta anormal daFC ao dipiridamol a DRC, a idade mais elevada e a disfunção ventricular esquerda. Conclusões: Há relação entre DRC e a resposta anormal da FC ao dipiridamol, mas a FAV não explica a influência da doença renal sobre essa resposta.

Background: An abnormal heart rate (HR) response to dipyridamole occurs in patients with chronic renal disease for unknown reasons. A broad-ranging review of the literature did not disclose any studies on the contribution of arteriovenous fistula (AVF) to this phenomenon. Objective: To evaluate the role of AVF in reduced HR response to dipyridamole in patients with CRFundergoing myocardial perfusion scintigraphy. Methods: 516 adult patients were studied, 45 with CRF(25 with AVF and 20 without AVF) and 471 with normal kidney function, consecutively undergoing myocardialscintigraphy in a tertiary care hospital between 2006 and 2009. Hemodynamic responses to dipyridamole wereevaluated in all these patients, as well as clinical and scintigraphic parameters. An abnormal HR response to dipyridamole was defined as the peak HR/basal HR≤1.2 ratio and the difference as the peak HR-HR basal<12bpm. Results: The reduced HR response to dipyridamole was equivalent in both groups of CRF patients (with or without AVF), although more frequent than in patients without CRF (68% vs 70.0% vs 29.7%, p<0.001, respectively). Using logistic regression, the predictors of an abnormal HR response to dipyridamole were found to be the presence of CRF, older age and left ventriculardysfunction. Conclusions: There is a link between CRF and the abnormal HR response to dipyridamole, but the presence of AVF does not explain the influence of kidney disease on this response.

Influência do uso do bicarbonato de sódio na cintilografia miocárdica com tálio-201 para pesquisa de viabilidade miocárdica / Influence of sodium bicarbonate in myocardial scintigraphy with 201TL for myocardial viability assessment

Fundamentos: Estudos já publicados demonstraram que o bicarbonato de sódio administrado 30 minutos antes da injeção do Tálio-201 aumenta a captação de Tálio-201 durante o estresse físico. A influência da alcalose sanguínea transitória em seres humanos antes do Tálio-201 injetado em repouso é desconhecida. Objetivo: Avaliar a influência e segurança do uso do bicarbonato de sódio na cintilografia miocárdica com Tálio-201 para pesquisa de viabilidade miocárdica. Metodologia: Entre 4/2009 e 12/2009, 15 pacientes foram submetidos à cintilografia de perfusão miocárdica comTálio-201, segundo o protocolo de repouso-redistribuição (protocolo-padrão) e uma semana depois, repetiam o exame, quando era infundido 2mEq/kg de bicarbonato de sódio a 8,4% por via intravenosa, 30 minutos antes da injeção do radiotraçador.Resultados: As imagens do protocolo com bicarbonato revelaram um número de segmentos normais maior, escoresde perfusão menores e menor número de segmentos com reversibilidade do que o protocolo tradicional. O percentual de segmentos sem reversibilidade foi equivalente em ambos os protocolos. Não houve qualquer tipo de complicaçãorelacionada ao protocolo com bicarbonato. Conclusões: A injeção de bicarbonato de sódio antes do Tálio-201 é segura e aumentou a captação do Tálio-201 pelo miócito, resultando em menor quantidade de segmentos com defeitos de perfusão quando comparada ao protocolo-padrão. Embora haja redução do número de segmentos com reversibilidade nas imagens tardias, não houve aumento dos segmentos sem viabilidade no protocolo com bicarbonato.

Background: Published studies have already demonstrated that sodium bicarbonate administered 30 minutes before a 201Tl injection increases 201Tl uptake during physical stress. The influence of transient blood alkalosis in humans prior to injecting 201Tl at rest is unknown. Objective: To evaluate the influence and safety of sodiumbicarbonate used during myocardial scintigraphy with 201Tl for myocardial feasibility assessment. Methods: Between April and December 2009, fifteen patients underwent rest-redistribution 201Tl myocardial perfusion scintigraphy (standard protocol), repeated 1 week later, when 2mEq/kg of sodium bicarbonate were injected intravenously 30 minutes before the radiotracer injection. Results: The bicarbonate protocol images revealed more normal segments, with lower perfusion scores and fewer reversible segments than in the standard protocol. The percentage of non-reversible segments was equivalent in both protocols. There were no complications related to the bicarbonate protocol.Conclusions: Sodium bicarbonate injections before 201Tl are safe and enhance the 201Tl uptake by the myocyte resulting in fewer segments with perfusion defects, compared to the standard protocol. Despite a reduction inthe number of reversible segments in the later images, there was no increase in nonviable segments in the bicarbonateprotocol.