Angioplastia Coronária no Enfarte Agudo do Miocárdio: Impacto do Timing da Revascularização na Alternância da Onda Ta

Encontra-se bem estabelecido que, na abordagem terapêutica do enfarte agudo do miocárdio (EAM), a trombólise e a angioplastia coronária percutânea (ACTP) permitem diminuir a mortalidade e melhorar o prognóstico, sendo esse benefício tanto maior quanto menor o tempo decorrido entre o evento isquémico e o procedimento terapêutico. No entanto, não está ainda estabelecido qual o impacto que o atraso da implementação dessas terapêuticas tem no desenvolvimento de taquidisritmias ventriculares e por consequência no resultado da alternância da onda T(TWA), que representa um método reconhecido para avaliação da vulnerabilidade ventricular às referidas arritmias. Objectivo: Analisar os resultados da TWA por microvoltagem numa população submetida a ACTP na sequência de EAM e avaliar a influência do timing de revascularização miocárdica nos resultados da TWA. Métodos: Estudámos 79 doentes (67 do sexo masculino; 57 ± 11 anos) consecutivos, admitidos por EAM e sujeitos a revascularização miocárdica por ACTP durante o internamento. A TWA foi avaliada utilizando um aparelho da HeartTwave System (Cambridge Heart, Inc., Bedford, Massachusetts) nos 30 dias pós-EAM. Durante a realização de uma prova de esforço em tapete rolante com protocolo manual, com o objectivo de elevar a frequência cardíaca até aos 110 batimentos por minuto, realizou-se o registo electrocardiográfico através da aplicação de sete eléctrodos standard e outros sete eléctrodos sensores de alta-resolução, especialmente concebidos para redução do «ruído», dispostos segundo as derivações ortogonais de Frank(X,Y, Z). A TWA foi considerada positiva quando se verificou a presença de alternância da onda T de magnitude ³ 1,9 μV de forma consistente e mantida (> 1 minuto), com início para frequências cardíacas < 110 batimentos/minuto ou quando esta alternância se verificou em doentes em repouso. Foi considerada negativa quando se conseguiu obter dados sem artefactos durante pelo menos um minuto, com frequências > 105 batimentos/minuto, sem atingir critério de positividade e indeterminada se não podia ser classificada como positiva ou negativa. Foram excluídos doentes com EAM ou revascularização miocárdica (cirúrgica ou percutânea) prévios, os que apresentavam insuficiência cardíaca congestiva, com fibrilhação auricular, > 10 extrassístoles por minuto, pacemaker definitivo, bradicárdia < 40 bpm, complexos QRS com duração > 130 ms ou sob terapêutica anti-arrítmica. Considerámos como marcador de risco para a ocorrência de eventos arrítmicos ventriculares malignos a presença de TWA positiva ou indeterminada. (TWA «nãonegativa»). Os resultados da TWA foram comparados entre o grupo de doentes submetidos a ACTP nas primeiras 24 horas pós-EAM (Grupo A; n = 45) e o grupo de doentes submetidos a ACTP > 24 horas pós-EAM. (Grupo B; n = 34) Resultados: A TWA foi positiva em 16 doentes (20,2%) e negativa em 56 (70,9%). Em 7 casos (8,9%), o resultado do teste foi considerado indeterminado. A TWA foi «não-negativa» em 29,1% da população. No grupo A a TWA foi “não-negativa” em 9 doentes (20 %) (6 com TWA positiva e três com TWA indeterminada) e negativa em 36 doentes (80 %) e no grupo B foi «não-negativa» em 14 doentes (41%) (10 com TWA positiva e quatro com TWA indeterminada) e negativa em 20 (59 %) (p < 0,05). Não se encontraram diferenças entre os dois grupos no que respeita à fracção de ejecção ventricular esquerda. No seguimento até aos 60 dias após a alta hospitalar não foram documentados eventos arrítmicos ventriculares, síncopes ou óbito. Foram reinternados cinco doentes (7 %) por recorrênciade angor. Conclusões: Numa população de sobreviventes de EAM encontrámos uma prevalência de TWA não negativa de 29 %, apesar da revascularização miocárdica com ACTP. A ACTP, quando efectuada nas primeiras 24 horas após o início do EAM, reduz de forma significativa o número de doentes com TWA não negativa,sugerindo que esta intervenção precoce poderá baixar o risco arrítmico destes doentes e influenciar favoravelmente o prognóstico pós-EAM. O impacto da morte súbita na mortalidade pós-EAM justifica estudos prospectivos de maiores dimensões

Terapêutica Trombolítica no Enfarte Agudo do Miocárdio: Motivos de Inelegibilidade

STUDY OBJECTIVE: to establish the reasons of ineligibility for thrombolytic therapy (TL) in a group of patients with acute myocardial infarction (AMI). DESIGN: retrospective analysis of protocols and clinical records. SETTING: the medical intensive care unit (ICU) of a tertiary care hospital. PATIENTS AND METHODS: we studied the records from patients with AMI admitted to the ICU during a five-year period (1987-91) and excluded from TL, to determine the cause(s) of ineligibility. RESULTS: we found 1669 patients with AMI, 89 of which were excluded from the study. Of the remaining 1580 patients, 1274 (80.6%) did not receive TL. Mean age was 64.4 years; 66.4% were men. Mortality was 24.6%. Mean duration of chest pain was 19.4 hours. Chief reasons for exclusion from TL were advanced age (43.1% of patients) and delayed presentation (55.7%); one of these was present in 79.2%. CONCLUSIONS: this study confirmed the high mortality of patients with AMI who do not receive TL. Advanced age and delayed presentation were the main causes of ineligibility. As age is being abandoned as an exclusion criterion, efforts for expansion of TL should center on the earlier arrival of patients to centers where it is available.

Variações de Marcadores Inflamatórios no Enfarte Agudo do Miocárdio: um Estudo Longitudinal

Actualmente a inflamação é considerada uma componente importante na aterosclerose, desde o seu início até à ruptura da placa seguida de trombose e da progressiva obstrução do vaso. A ruptura da cápsula fibrótica da placa expõe factores de tecido presentes no seu núcleo necrótico que induzem o processo inflamatório, promovendo a adesão celular e a coagulação e que conduzem à formação do trombo. Por seu turno, várias citocinas e moléculas de adesão celular contribuem activamente para o desenvolvimento da placa. Em particular a citocina TNF-a e a molécula de adesão intercelular (ICAM-1) poderão ser indicadoras de inflamação enquanto que as formas solúveis de P-selectina e de CD40 ligando (sCD40L) poderão dar a magnitude da activação plaquetária. Neste trabalho foram estudados 17 doentes com enfarte de miocárdio submetidos a angioplastia (grupo AMI) e 16 doentes com confirmação angiográfica de ausência de doença coronária. Os doentes do grupo AMI foram seguidos nas primeiras 24h de evolução do enfarte agudo de miocárdio antes da administração de medicação e da intervenção angiográfica e ao longo do período de recuperação, 2 e 40 dias após enfarte. Foram medidas no soro por imunoensaio as concentrações de TNF-a e das formas solúveis de CD40L, ICAM-1 e P-selectina. Foram observadas variações significativas de sP-selectina relativamente aos controlos. Imediatamente após o enfarte de miocárdio verificou-se um aumento de sP-selectina, seguido de uma descida brusca dos seus níveis às 48h, e de um incremento para valores idênticos aos observados no grupo de controlo ao 40º dia. As variações observadas nas concentrações de sCD40L não foram significativas relativamente aos controlos. No entanto, verificou-se uma tendência de diminuição da concentração até 48h após o enfarte de miocárdio, seguindo-se um aumento que atingiu valores ligeiramente superiores ao do grupo controlo no 40º dia. As concentrações de TNF-a medidas foram sistematicamente superiores às verificadas no grupo controlo, tendo-se ainda observado uma subida gradual desde o enfarte de miocárdio até ao 40º dia, sendo este incremento significativo. Os valores de sICAM-1 não apresentaram quaisquer variações após o enfarte nem relativamente ao grupo controlo. As variações observadas sugerem um papel importante destes marcadores no processo inflamatório e na evolução do enfarte de miocárdio. O aumento brusco da concentração de sP-selectina após o enfarte de miocárdio evidencia a activação plaquetária e trombose. Na evolução do enfarte, e à medida que as variáveis hemodinâmicas retornam a valores estáveis, devido à medicação aplicada, o aumento de sCD40L e TNF-a em circulação pode reflectir o papel destas moléculas na recuperação endotelial e do miocárdio.

Impacto da Idade no Tratamento e Resultados Após Enfarte Agudo do Miocárdio em Particular nos Muito Idosos

INTRODUCTION: The elderly population admitted for acute myocardial infarction is increasing. This group is not well studied in international trials and is probably treated with a more conservative approach. OBJECTIVES: To evaluate the presentation and treatment of myocardial infarction according to age, particularly in very elderly patients. METHODS: We studied 1242 consecutive patients admitted with acute myocardial infarction, assessing in-hospital, 30-day and one-year mortality during follow-up for each age-group. Patients were divided into four groups according to age: <45 years (7.6%); 45-64 years (43.3%); 65-74 years (23.4%); and ≥75 years (25.7%). RESULTS: Elderly patients had a worse risk profile (except for smoking), more previous history of coronary disease and a worse profile on admission, with the exception of lipid profile, which was more favorable. With regard to treatment of the elderly, although less optimized than in other age-groups, it was significantly better compared to other registries, including for percutaneous coronary angioplasty. Both complications and mortality were worse in the older groups. In elderly patients (≥75 years), adjusted risk of mortality was 4.9-6.3 times higher (p<0.001) than patients in the reference age-group (45-64 years). In these patients, the independent predictors of death were left ventricular function and renal function, use of beta-blockers being a predictor of survival. CONCLUSIONS: Elderly patients represent a substantial proportion of the population admitted with myocardial infarction, and receive less evidenced-based therapy. Age is an independent predictor of short- and medium-term mortality.

Enfarte Agudo do Miocárdio Associado a Origem Anómala das Artérias Coronárias (um Caso Raro de Origem da Artéria Coronária Direita)

A origem da artéria coronária esquerda a partir do ostio ou do segmento proximal da artéria coronária direita é uma anomalia congénita rara (0,03 a 0,4%), e um achado angiográfico pouco comum (0,6 a 1,3%) (artéria coronária única). A anomalia congénita coronária mais frequente é a origem separada da artéria descendente anterior e da artéria circunflexa no seio coronário esquerdo. A segunda anomalia mais comum é a origem da artéria circunflexa no seio coronário direito. Descrevemos um caso de enfarte agudo do miocárdio com localização infero lateral, que evoluiu com choque cardiogénico e disfunção ventricular esquerda graves, após angioplastia primária de oclusão proximal da artéria coronária direita, e em que não foi possível cateterizar a artéria coronária esquerda por inexistência de ostio no seio coronário esquerdo. Destaca-se o papel importante das novas técnicas de imagem, nomeadamente da angio-TC das coronárias, na identificação das anomalias congénitas das artérias coronárias.

Enfarte Agudo do Miocárdio no Puerpério

Os autores descrevem um caso clínico de paciente de 42 anos, com enfarte agudo do miocárdio (EAM) ao 3º dia de puerpério, tendo efectuado angioplastia directa. A propósito deste caso fez-se uma revisão das principais alterações fisiológicas cardiovasculares e da hemostase na gravidez, habitualmente bem toleradas pelas gestantes, mas que em mulheres com factores de risco ou com doença cardíaca prévia aumentam a probabilidade de eventos cardiovasculares. O volume sanguíneo e o débito cardíaco aumentam em média 50% durante a gestação, a concentração de hemoglobina diminui e a menor resistência vascular periférica condiciona uma queda da pressão arterial na primeira metade da gravidez. No pós parto imediato verifica-se um incremento na pressão de enchimento ventricular, volume sistólico e débito cardíaco e é no período peri-parto que o risco cardiovascular se encontra mais elevado. A incidência de EAM na gravidez e puerpério é baixa, no entanto a tendência é de aumento, tendo em conta o número crescente de gestações nos extremos da idade reprodutiva.

Safety and Effectiveness of the Genous Endothelial Progenitor Cell-Capture Stent: Follow-Up to 5 Years

AIMS: To evaluate the long-term clinical outcomes following percutaneous coronary intervention (PCI) with the Genous stent in an unselected population. METHODS: All patients admitted to a single center who underwent PCI using the GS exclusively, between May 2006 and May 2012, were enrolled, and a clinical follow-up of up to 60 months was carried out. The primary endpoint of major adverse cardiac event (MACE) rate was defined as the composite of cardiac death, acute myocardial infarction (AMI), and target lesion revascularization (TLR). RESULTS: Of the 450 patients included (75.1% male; 65.5 ± 11.7 years), 28.4% were diabetic and acute coronary syndrome was the reason for PCI in 76.4%. Angioplasty was performed in 524 lesions using 597 Genous stents, with angiographic success in 97.1%. At a median of 36 months of follow-up (range, 1-75 months), MACE, AMI, TLR, stent restenosis (SR), and stent thrombosis (ST) rates were 15.6%, 8.4%, 4.4%, 3.8%, and 2.2%, respectively. Between 12 and 24 months, the TLR, SR, and ST rates practically stabilized, up to 60 months. Bifurcation lesions were independently associated with MACE, TLR, and SR. CONCLUSION: This is the first study reporting clinical results with the Genous stent up to 60 months. The Genous stent was safe and effective in the long-term, in an unselected population.

Economic Evaluation of Ticagrelor for Secondary Prevention Following Acute Coronary Syndromes

INTRODUCTION AND OBJECTIVES: To estimate the cost-effectiveness and cost-utility of ticagrelor in the treatment of patients with acute coronary syndromes (unstable angina or myocardial infarction with or without ST-segment elevation), including patients treated medically and those undergoing percutaneous coronary intervention or coronary artery bypass grafting. METHODS: A short-term decision tree and a long-term Markov model were used to simulate the evolution of patients' life-cycles. Clinical effectiveness data were collected from the PLATO trial and resource use data were obtained from the Hospital de Santa Marta database, disease-related group legislation and the literature. RESULTS: Ticagrelor provides increases of 0.1276 life years and 0.1106 quality-adjusted life years (QALYs) per patient. From a societal perspective these clinical gains entail an increase in expenditure of €610. Thus the incremental cost per life year saved is €4780 and the incremental cost per QALY is €5517. CONCLUSIONS: The simulation results show that ticagrelor reduces events compared to clopidogrel. The costs of ticagrelor are partially offset by lower costs arising from events prevented. The use of ticagrelor in clinical practice is therefore cost-effective compared to generic clopidogrel.

External Validation of the ProACS Score for Risk Stratification of Patients with Acute Coronary Syndromes

INTRODUCTION: The ProACS risk score is an early and simple risk stratification score developed for all-cause in-hospital mortality in acute coronary syndromes (ACS) from a Portuguese nationwide ACS registry. Our center only recently participated in the registry and was not included in the cohort used for developing the score. Our objective was to perform an external validation of this risk score for short- and long-term follow-up. METHODS: Consecutive patients admitted to our center with ACS were included. Demographic and admission characteristics, as well as treatment and outcome data were collected. The ProACS risk score variables are age (≥72 years), systolic blood pressure (≤116 mmHg), Killip class (2/3 or 4) and ST-segment elevation. We calculated ProACS, Global Registry of Acute Coronary Events (GRACE) and Canada Acute Coronary Syndrome risk score (C-ACS) risk scores for each patient. RESULTS: A total of 3170 patients were included, with a mean age of 64±13 years, 62% with ST-segment elevation myocardial infarction. All-cause in-hospital mortality was 5.7% and 10.3% at one-year follow-up. The ProACS risk score showed good discriminative ability for all considered outcomes (area under the receiver operating characteristic curve >0.75) and a good fit, similar to C-ACS, but lower than the GRACE risk score and slightly lower than in the original development cohort. The ProACS risk score provided good differentiation between patients at low, intermediate and high mortality risk in both short- and long-term follow-up (p<0.001 for all comparisons). CONCLUSIONS: The ProACS score is valid in external cohorts for risk stratification for ACS. It can be applied very early, at the first medical contact, but should subsequently be complemented by the GRACE risk score.

Utilização de Stents Revestidos com Fármaco em Angioplastia Primária - Resultados Clínicos a Longo Prazo

INTRODUCTION: The use of drug-eluting stents in the context of mechanical reperfusion following ST-segment elevation myocardial infarction (MI) was initially viewed with concern. The main fear was that the drugs' action in unstable lesions could increase the risk of thrombotic stent occlusion. Furthermore, there was no evidence that the proven benefit of reduced instent restenosis could be extended to such patients, since they were excluded from the initial clinical trials. OBJECTIVES: To assess the safety and long-term clinical outcomes of the use of drug-eluting stents in primary angioplasty. METHODS: The first 100 consecutive and non-selected patients admitted for MI and treated by primary angioplasty with drug-eluting stent implantation in the target lesion were analyzed retrospectively. The efficacy and safety of the procedure, in-hospital clinical evolution and the occurrence of major adverse cardiac events in the first year were assessed. RESULTS: Patients' mean age was 58.2 +/- 11.5 years, and 78 were male. The success rate of primary angioplasty was 99%. Stents coated with sirolimus were used in 67 patients, paclitaxel in 19 and dexamethasone in 16. In-hospital mortality was 3%. The follow-up rate at 12 months was 98%. During this period, the rate of target vessel revascularization was 1% (with no patient requiring target lesion revascularization), MI 2%, and overall mortality 3.9%. Fourteen patients had clinical indication for repeat coronary angiography, which showed no significant in-stent restenosis. One event was considered to be due to acute stent thrombosis. The incidence of major adverse events was 5.9%. CONCLUSION: The use of drug-eluting stents in MI patients undergoing primary mechanical revascularization is safe and is associated with a reduced incidence of major adverse events, thrombosis and clinical restenosis at one year.

Trombose Muito Tardia de Stent Coronário Após Suspensão de Terapêutica Antiagregante Plaquetária

Percutaneous transluminal coronary angioplasty (PTCA) with stent placement is widely used to achieve myocardial revascularization in patients with symptomatic ischemic heart disease and significant coronary artery stenosis. Drug-eluting stents are used in most patients undergoing percutaneous angioplasty. Stent thrombosis is an uncommon but serious complication, manifested mostly by sudden death or acute ST-elevation myocardial infarction. The authors report the case of a 68-year-old patient with acute anterior ST-elevation myocardial infarction. Five years previously, she had had a similar presentation and underwent primary angioplasty of the left anterior descending artery with implantation of a drug-eluting stent. The patient was discharged under antithrombotic therapy. She discontinued antiplatelet therapy and two days later suffered an acute anterior myocardial infarction. Primary angioplasty revealed stent thrombosis.

Origem Anómala da Artéria Coronária Esquerda a Partir da Artéria Pulmonar

OBJECTIVE: To assess the frequency and severity of the anomalous origin of the left coronary artery (ALCA) from the pulmonary artery (PA). DESIGN OF THE STUDY: Prospective study of case series between March 1991 and December 1994. SETTING: Referral-based Paediatric Cardiology Department of a Tertiary Care Center. PATIENTS AND METHODS: Five consecutive patients (pts) with anomalous origin of the LCA from the PA; there were three infants aged 4 months and two children one 8 year and one 9 year old. There were three girls and two boys. All pts had clinical and 2D-echo and Doppler investigation prior to cardiac catheterization (CC). Indication for CC was based in the association of symptoms and signs of myocarditis or dilated cardiomyopathy of acute or subacute onset and electrocardiographic (ECG) signs of ischemia in infants. In older patients (pts) diagnosis was suspected mainly from ECG. During CC in all pts, aortograms and when necessary selective coronary angiograms were performed. Surgical correction was performed in all children. In two pts stress exercise ECG and stress Thallium studies before and after surgery were performed. RESULTS: two pts had "adult" an three had "infantile" type of ALCA from the PA. CC was performed and diagnosis was confirmed at surgery in all cases. In one child, correct diagnosis was made by ECO prior to CC and in one case LCA to PA fistula was suspected on Colour-Doppler study. No complications were attributed to CC. Several types of surgery were performed: reimplantation of the ALCA from the PA to the aorta (three pts); tunnel connection of the aorta to the ALCA via the PA (one pt) and left internal mammary to LCA anastomosis (one pt). Two infants died intraoperatively due to extensive myocardial infarction and poor left ventricular function. All the three survivors are asymptomatic after a mean follow up of 34 months. Two oldest pts are currently in New York Heart Association functional class I with normal ECG and improved myocardial perfusion on Thallium scan despite almost total occlusion of LCA at the site of implantation in the aorta as diagnosed on coronary angiogram. CONCLUSIONS: ALCA from PA is associated with major morbidity and mortality. Diagnosis should be suspected in pts with unexplained myocardial ischemia on ECG and even more if it is associated to clinical signs of dilated cardiomyopathy or myocarditis. Careful assessment on ECO and pulsed Doppler and colour flow mapping should make the diagnosis in most cases. Although surgery can be performed based only on ECO diagnosis, we strongly advise for angiography in all cases as in our experience there are false negative diagnosis by ECO. Preoperative Thallium studies can be useful for the selection of the type of surgery as pts with very little viable myocardium will not survive the establishment of a direct systemic to coronary blood flow and may be candidates for heart transplantation.