Acute myocardial infarction after noncardiac surgery

Em todo o mundo, são realizadas mais de 230 milhões de operações por ano e as complicações cardíacas são as causas mais comuns de morbidade e mortalidade pós-operatórias. Com o aumento da expectativa de vida da população mundial, um número crescente de pacientes com múltiplas comorbidades tem sido submetido a operações não cardíacas. Em consequência, é esperado um aumento de complicações cardiovasculares associadas a tais procedimentos e o infarto agudo do miocárdio (IAM) perioperatório poderá se tornar um problema frequente. No Brasil, o número de operações não cardíacas também está aumentando, sendo realizadas aproximadamente três milhões de cirurgias por ano. Apesar dos avanços nas técnicas cirúrgicas e anestésicas, a mortalidade e o custo relacionados a estes procedimentos também estão aumentando, sendo fundamental o desenvolvimento de estratégias para a redução da mortalidade. A ocorrência de um IAM perioperatório prolonga a necessidade de terapia intensiva, a estadia hospitalar, aumenta o custo da internação e diminui a sobrevida a longo prazo. Esta revisão aborda a fisiopatologia, a incidência, o diagnóstico e o tratamento do IAM perioperatório, baseado nas evidências atuais

Aspirin responsiveness safely lowers perioperative cardiovascular risk

IntroductionVascular surgeries are related to high cardiac morbidity and mortality, and the maintenance of aspirin in the perioperative period has a protective effect. The purpose of this study was to evaluate the association between preoperative platelet aggregability and perioperative cardiovascular (CV) events.MethodsA preoperative platelet aggregation test was performed on an impedance aggregometer in response to collagen and to arachidonic acid (AA) for 191 vascular surgery patients under chronic use of aspirin. We analyzed the following CV events: acute myocardial infarction, unstable angina, isolated troponin elevation, acute ischemic stroke, reoperation, and cardiac death. Hemorrhagic events were also evaluated and classified according to the Thrombolysis In Myocardial Infarction criteria.ResultsThe incidence of CV events was 22% (n = 42). Higher platelet response to AA was associated with CV events, so that patients in the fourth quartile (higher than 11Ω) had almost twice the incidence of CV events when compared with the three lower quartiles: 35% vs 19%; P = .025. The independent predictors of CV events were hemodynamic instability during anesthesia (odds ratio [OR], 4.12; 95% confidence interval [CI], 1.87-9.06; P < .001), dyslipidemia (OR, 3.9; 95% CI, 1.32-11.51; P = .014), preoperative anemia (OR, 2.64; 95% CI, 1.19-5.85; P = .017), and AA platelet aggregability in the upper quartile (OR, 2.48; 95% CI, 1.07-5.76; P = .034). Platelet aggregability was not associated with hemorrhagic events, even when we compared the lowest quartile of AA platelet aggregability (0-1.00 Ω) with the three upper quartiles (>1.00 Ω; OR, 0.77; 95% CI, 0.43-1.37; P = .377).ConclusionsThe degree of aspirin effect on platelet aggregability maybe important in the management of perioperative CV morbidity, without increment in the bleeding toll

Incremental value of B-type natriuretic peptide for early risk prediction of infective endocarditis

SummaryBackgroundEarly and accurate risk prediction is an unmet clinical need in patients with infective endocarditis (IE). The aim of this study was to determine the value of B-type natriuretic peptide (BNP) levels obtained on admission for the prediction of in-hospital death in IE patients.MethodsBetween 2009 and 2011, consecutive patients with IE diagnosed using the revised Duke criteria and admitted to the emergency department were evaluated prospectively. BNP levels were measured on admission. Death during hospitalization was the primary endpoint.ResultsAmong 104 consecutive patients with IE and with available BNP levels, 34 (32.7%) died in hospital. BNP levels were significantly higher in patients who died as compared to survivors (709.0 pg/ml vs. 177.5 pg/ml, p<0.001). The accuracy of BNP to predict death as quantified by the area under the receiver operating characteristics curve was 0.826 (95% confidence interval (CI) 0.747–0.905). The value of BNP was additive to that provided by clinical, microbiological, and echocardiography assessment. On multivariate analysis, new heart failure (hazard ratio (HR) 2.02, 95% CI 1.15–3.57, p=0.015), sepsis (HR 2.10, 95% CI 1.25–3.55, p=0.005), Staphylococcus aureus endocarditis (HR 2.67, 95% CI 1.60–4.45, p<0.001), left ventricular ejection fraction ≤55% (HR 1.63, 95% CI 1.00–2.65, p=0.047), and BNP (HR 1.04, 95% CI 1.02–1.06, p<0.001) were independent predictors of in-hospital mortality.ConclusionAmong patients with IE, BNP levels obtained on admission provide incremental value for early and accurate risk prediction

Non-Cardiac Surgery in Developing Countries: Epidemiological Aspects and Economical Opportunities – The Case of Brazil

Background: Worldwide distribution of surgical interventions is unequal. Developed countries account for the majority of surgeries and information about non-cardiac operations in developing countries is scarce. The purpose of our study was to describe the epidemiological data of non-cardiac surgeries performed in Brazil in the last years. Methods and Findings: This is a retrospective cohort study that investigated the time window from 1995 to 2007. We collected information from DATASUS, a national public health system database. The following variables were studied: number of surgeries, in-hospital expenses, blood transfusion related costs, length of stay and case fatality rates. The results were presented as sum, average and percentage. The trend analysis was performed by linear regression model. There were 32,659,513 non-cardiac surgeries performed in Brazil in thirteen years. An increment of 20.42% was observed in the number of surgeries in this period and nowadays nearly 3 million operations are performed annually. The cost of these procedures has increased tremendously in the last years. The increment of surgical cost was almost 200%. The total expenses related to surgical hospitalizations were more than $10 billion in all these years. The yearly cost of surgical procedures to public health system was more than$1.27 billion for all surgical hospitalizations, and in average, U$445.24 per surgical procedure. The total cost of blood transfusion was near$98 million in all years and annually approximately $10 million were spent in perioperative transfusion. The surgical mortality had an increment of 31.11% in the period. Actually, in 2007, the surgical mortality in Brazil was 1.77%. All the variables had a significant increment along the studied period: r square (r(2)) = 0.447 for the number of surgeries (P = 0.012), r(2) = 0.439 for in-hospital expenses (P = 0.014) and r(2) = 0.907 for surgical mortality (P = 0.0055). Conclusion: The volume of surgical procedures has increased substantially in Brazil through the past years. The expenditure related to these procedures and its mortality has also increased as the number of operations. Better planning of public health resource and strategies of investment are needed to supply the crescent demand of surgery in Brazil.Scholarship Program of Cardiology Society of Sao Paulo (SOCESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

Angiographic features of acute coronary syndromes after non cardiac surgeries

No Brasil são realizadas aproximadamente três milhões de cirurgias por ano. Apesar dos avanços nas técnicas cirúrgicas e anestésicas, a mortalidade e o custo relacionados a estes procedimentos estão aumentando, sendo fundamental o desenvolvimento de estratégias para redução da mortalidade. A ocorrência de um infarto agudo do miocárdio (IAM) perioperatório prolonga a estadia hospitalar e aumenta a mortalidade. A fisiopatologia do IAM perioperatório pode envolver a instabilização de placas de ateroscleose com trombose ou o desbalanço entre oferta e consumo de oxigênio secundário à anemia ou hipotensão. Dependendo do mecanismo predominante, o prognóstico e tratamento podem ser diferentes. Apesar disto, faltam estudos clínicos desenhados para estabelecer a fisiopatologia do IAM perioperatório em pacientes que sobreviveram a estes eventos. O achado de lesões complexas na cineangiocoronariografia, embora possa ocorrer em pacientes com doença arterial coronária (DAC) estável, é mais freqüente em pacientes com angina instável e IAM, estando claramente relacionado com ruptura e instabilização da placa. O objetivo deste estudo foi comparar os achados angiográficos, incluindo as características das lesões coronarianas, em pacientes divididos em três grupos diagnósticos distintos: Síndromes Coronarianas Agudas (SCA) após operações não cardíacas, SCA espontâneas e doença arterial coronária estável. Entre fevereiro de 2006 e junho de 2010, foram avaliadas e comparadas as características clínicas e angiográficas de 120 pacientes com SCA após operações não cardíacas (grupo SCAPO), 120 pacientes que procuraram o serviço de emergência com SCA espontâneas (grupo SCAES) e 240 pacientes do ambulatório de DAC crônica (grupo DAC crônica). Os filmes das cineangiocoronariografias foram avaliados por um hemodinamicista experiente sem conhecimento do diagnóstico clínico. As cineangiocoronariografias foram avaliadas quanto ao número, localização e presença de lesões do tipo II da Classificação de Ambrose e de lesões complexas. Quatrocentos e oitenta pacientes e 1470 lesões foram avaliadas. Não houve diferença entre os grupos com relação ao sexo (p=0,51), à prevalência de diabetes (p=0,23) ou hipertensão arterial sistêmica (p=0,837). Os pacientes do grupo SCAPO eram mais idosos do que os dos grupos SCAES e DAC crônica (média de idade 67,8 anos x 64,5 anos x 61,9 anos, respectivamente; p<0,001). No grupo SCAPO, 45% dos pacientes apresentavam lesões do tipo II da Classificação de Ambrose x 56,7% dos pacientes do grupo SCAES e 16,4% dos pacientes do grupo DAC crônica (p<0,001). Os pacientes do grupo SCAES apresentaram maior número de lesões complexas do que aqueles do grupo SCAPO, que, por sua vez, apresentaram maior número de lesões complexas do que os pacientes do grupo DAC crônica (79,2% x 56,7% x 31,8%; p< 0,001). Concluímos que, em pacientes com SCA perioperatórias e SCA espontâneas, as lesões complexas e lesões do tipo II da classificação de Ambrose são mais freqüentes do que em pacientes com DAC estável e em aproximadamente metade dos casos SCA perioperatória ocorre a instabilização e ruptura de placa desencadeando um IAM tipo 1Annually, nearly three million noncardiac surgeries are performed in Brazil. Despite improvements in surgical and anesthetic techniques, mortality and cost related to these procedures are raising. Strategies for reducing mortality are needed. Patients experiencing a myocardial infarction (MI) after noncardiac surgeries have a high mortality and prolonged hospital stay. The pathophysiology of acute coronary syndrome (ACS) in the perioperative setting may involve thrombosis over a vulnerable plaque or decreased oxygen supply secondary to anemia or hypotension. Depending on the predominant mechanism, prognosis and treatment may be different. There are no studies designed to establish this pathophysiology in patients that survived a perioperative MI. Although the presence of complex lesions in coronary angiography may occur in stable coronary artery disease (CAD) patients, it is far more common in unstable angina and MI and, strongly associated to plaque disruption. The purpose of this study was to compare the angiographic characteristics between ACS in the perioperative setting (PACS), in the emergency room - spontaneous ACS (SACS), and stable CAD patients. Between February 2006 and June 2010 clinical and angiographic data were prospectively recorded into a database for consecutive patients that had ACS after noncardiac surgery (n=120), and for 120 patients with SACS. We also collected data for a control group of 240 patients with stable CAD. All angiographies were analyzed by a single expert observer who was unaware of the patients clinical diagnosis. The number and location of coronary lesions with obstructions greater than 50% were recorded. Each lesion was classified based on Ambroses classification and if they had a complex morphology. The presence of Ambroses type II and complex lesions was compared between the three groups. Four hundred and eighty patients and 1470 lesions were analyzed. There were no differences between the three groups in the prevalence of male sex (p=0.521), hypertension (p=0.837) or diabetes (p=0.230). Patients in PACS were older than patients of SACS or CAD groups (mean age 67.8±10.2 years x 64.5±12.4years x 61.9±9.7years, respectively; p<0.001). In PACS, 45% of patients had Ambroses type II lesions x 56.7% in SACS group and 16.4% in CAD group (p<0.001). Patients in PACS had less complex lesions than patients in SACS, but more lesions than patients in CAD group (56.7% x 79.2% x 31.8%, respectively; p< 0.001). In conclusion, patients with perioperative ACS and spontaneous SCA have more Ambroses type II and complex lesions than patients with stable CAD. Nearly 50% of patients with perioperative myocardial infarction have evidence of coronary plaque rupture, characterizing a type 1 M