Índice de anisocitose eritrocitária e disfunção endotelial

Introdução: O índice de anisocitose eritrocitária (RDW) foi recentemente apontado como indicador de risco cardiovascular e como possível marcador de disfunção fisiológica global. Um RDW elevado pode reflectir um estado inflamatório e elevado stress oxidativo ambos associados à progressão do processo aterosclerótico. A tonometria arterial periférica (PAT) é um método não invasivo para avaliação da função endotelial. Esta é aferida pelo índice de hiperemia reativa (RHI) que avalia as mudanças na amplitude das ondas de pulso em resposta à isquémia local (oclusão arterial temporária). A disfunção endotelial, por sua vez, é um sinal precoce do processo aterosclerótico. Objectivos: Determinar a associação entre os valores de RDW e de RHI, em doentes com disfunção endotelial documentada por tonometria arterial periférica (PAT). Material e métodos: Estudámos 239 doentes, admitidos por diferentes patologias na Unidade de Cuidados Intensivos de Cardiologia (UCIC) do nosso hospital e submetidos a PAT. Identificámos os doentes com disfunção endotelial e agrupamo-los de acordo com os tercis da distribuição de RDW para cada sexo (medido à data do referido exame). Avaliámos a eventual relação entre o os valores de RDW e de RHI, nestes doentes. A codificação, registo e análise estatística dos dados foi feita em SPSS - v19.0. Resultados: Do total de doentes estudados, 190 (79,5%) apresentavam disfunção endotelial, de acordo com os resultados da PAT (RHI≤2,3): 47% com RHI <1,7; 37% com RHI 1,7-2,1 e 16% com RHI 2,1-2,3. Destes 62% eram do sexo masculino. A média de idades encontrada foi 63 anos. O RDW destes doentes variou entre 11,9% e 21,3%. No sexo masculino, 41,5% apresentavam RDW elevado (≥ 13,7%) enquanto, no sexo feminino, apenas 18,1% apresentavam RDW superior ao valor de referência (≥ 14,4%). Aplicando o teste qui-quadrado para tendência linear, verificou-se que não existe associação estatisticamente significativa entre o valor de RDW e de RHI (p-value=0,838). Conclusões: Na amostra estudada, não se encontrou associação estatisticamente significativa entre os valores de RDW e RHI, pelo que consideramos que o RDW não é um bom marcador de disfunção endotelial. No entanto, a realização de estudos prospectivos com amostras de maiores dimensões e incluindo outras variáveis, serão necessários para esclarecer a relação entre o índice de anisocitose eritrocitária e disfunção endotelial

Early peripheral endothelial dysfunction predicts myocardial infarct extension and microvascular obstruction in patients with ST-elevation myocardial infarction.

INTRODUCTION AND OBJECTIVES: The role of endothelial dysfunction (ED) in patients with ST-elevation myocardial infarction (STEMI) is poorly understood. Peripheral arterial tonometry (PAT) allows non-invasive evaluation of ED, but has never been used for this purpose early after primary percutaneous coronary intervention (P-PCI). Our purpose was to analyze the relation between ED assessed by PAT and both the presence of microvascular obstruction (MVO) and infarct extension in STEMI patients. METHODS: ED was assessed by the reactive hyperemia index (RHI), measured by PAT and defined as RHI <1.67. Infarct extension was assessed by troponin I (TnI) release and contrast-enhanced cardiac magnetic resonance (ceCMR). MVO was assessed by ceCMR and by indirect angiographic and ECG indicators. An echocardiogram was also performed in the first 12 h. RESULTS: We included 38 patients (mean age 60.0±13.7 years, 29 male). Mean RHI was 1.87±0.60 and 16 patients (42.1%) had ED. Peak TnI (median 118 mg/dl, IQR 186 vs. 67/81, p=0.024) and AUC of TnI (median 2305, IQR 2486 vs. 1076/1042, p=0.012) were significantly higher in patients with ED, who also showed a trend for more transmural infarcts (63.6% vs. 22.2%, p=0.06) and larger infarct mass on ceCMR (median 17.5%, IQR 15.4 vs. 10.1/10.3, p=0.08). Left ventricular ejection fraction (LVEF) was lower and wall motion score index (WMSI) was higher on both echocardiogram and ceCMR in patients with ED. On ceCMR, MVO was more frequent in patients with RHI <1.67 (54.5% vs. 11.1%, p=0.03). ECG and angiographic indicators of MVO all showed a trend toward worse results in these patients. CONCLUSIONS: The presence of ED assessed by PAT 24 h after P-PCI in patients with STEMI is associated with larger infarcts, lower LVEF, higher WMSI and higher prevalence of MVO.info:eu-repo/semantics/publishedVersio

Score PAMI para previsão da mortalidade no enfarte agudo do miocárdio tratado com angioplastia primária

Introdução: Com base nos ensaios PAMI I e II, AIR-PAMI e STENT-PAMI, foi recentemente proposto um Score de Risco para prever a mortalidade dos doentes submetidos a angioplastia primária no contexto de enfarte agudo do miocárdio com elevação do segmento ST. O Score de Risco inclui apenas seis parâmetros. Sendo um dos primeiros instrumentos disponíveis para prever a mortalidade neste grupo de doentes, resulta de estudos controlados e com critérios de inclusão restritos. Assim, foi nosso objectivo avaliar se o Score de Risco PAMI se aplica a doentes do «mundo real». Métodos: Incluímos 149 doentes consecutivos submetidos a angioplastia primária (idade média 58,2 ± 13,6 anos, 113 homens) com seis meses de seguimento em ambulatório. Aplicámos o Score de Risco PAMI e dividimos os doentes em três grupos de pontuações: 0 a 2 (Grupo 1), 3 a 6 (Grupo 2) e 7 pontos (Grupo 3). Resultados: Após aplicação do Score de Risco PAMI, 68 doentes (46 %) foram incluídos no Grupo 1, 41 (27 %) no Grupo 2 e 40 (27 %) no Grupo 3. Os três grupos não apresentaram diferenças significativas em termos de tempo dor-balão. Observaram-se diferenças muito significativas entre os Grupos 1, 2 e 3 nas mortalidades imediata (0 %, 2,4% e 15 %; p = 0,001), intra- -hospitalar (2,9 %, 7,3% e 37,5%; p < 0,001), aos 30 dias (2,9 %, 7,3% e 37,5 %; p < 0,001) e aos seis meses (4,4%, 14,6 % e 45,0 %: p < 0,001). Conclusões: O Score de Risco PAMI é um instrumento prognóstico simples, baseado em parâmetros acessíveis e de fácil cálculo. Permite prever com segurança a mortalidade imediata, intra-hospitalar, aos 30 dias e aos seis meses dos doentes com enfarte agudo do miocárdio submetidos a angioplastia primária

Identificação electrocardiográfica da artéria relacionada com o enfarte em doentes com enfarte agudo do miocárdio inferior

Introdução: A mortalidade e morbilidade do enfarte agudo do miocárdio (EAM) de localização inferior são determinados, entre outros factores, pela artéria responsável pelo enfarte (ARE). Têm sido propostos diversos critérios electrocardiográficos para identificar a coronária direita (CD) e a circunflexa como ARE. Recentemente, foi proposto um novo critério para identificação da circunflexa (infradesnivelamento do segmento ST em aVR). Foi objectivo deste trabalho avaliar os critérios electrocardiográficos clássicos e o novo critério (aVR) na discriminação da ARE em doentes com EAM inferior. Métodos: Foram incluídos os doentes com EAM inferior submetidos a angioplastia primária, sendo avaliado o ECG na admissão na sala de hemodinâmica. Foram excluídos os doentes com antecedentes de enfarte e com perturbações da condução intraventricular. A artéria com a lesão mais grave foi considerada a ARE. Foram avaliados os seguintes critérios electrocardiográficos: Infradesnivelamento do segmento ST (Infra ST) em DI, supradesnivelamento do ST (Supra ST) em V1 e V2, Supra ST em DIII > DII, relação Infra ST V3/Supra ST DIII > 1,2 (critérios «clássicos») e Infra ST em aVR. Os desnivelamentos do segmento ST foram medidos 0,06 s após o ponto J. Resultados: Foram incluídos 53 doentes (idade média 59.1 ± 13.9 anos, 38 homens). A CD foi a ARE em 38 doentes e a Circunflexa em 15. Os dois grupos não apresentavam diferenças em termos de idade, sexo, número de vasos doentes, fluxo TIMI inicial e tempo dor-balão. Os critérios «Infra ST em D1», «Supra ST DIII > DII», «relação Infra ST V3/Supra ST DIII > 1,2» e «Infra ST V1 e V2» discriminaram a artéria relacionada com o enfarte. O novo critério «Infra ST aVR» identificou a ARE num número reduzido de casos (sensibilidade 33%, especificidade 71 %), sem significado estatístico. Conclusões: Os quatro critérios «clássicos» ajudaram a descriminar a ARE em doentes com EAM inferior, mas o mesmo não se verificou para o novo critério recentemente proposto (infra ST em aVR)

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The Index of Microcirculatory Resistance as a Predictor of Echocardiographic Left Ventricular Performance Recovery in Patients With ST-Elevation Acute Myocardial Infarction Undergoing Successful Primary Angioplasty.

BACKGROUND: This study aims to evaluate the relationship between IMR (Index of Microcirculatory Resistance) and the echocardiographic evolution of left ventricular (LV) systolic and diastolic performance after ST-elevation acute myocardial infarction (STEMI), undergoing primary angioplasty (P-PCI). METHODS: IMR was evaluated immediately after P-PCI. Echocardiograms were performed within the first 24 hours (Echo1) and at 3 months (Echo2): LV volumes, ejection fraction (LVEF), wall motion score index (WMSI), E/é ratio, global longitudinal strain (GLS), and left atrial volume were measured. RESULTS: Forty STEMI patients were divided in 2 groups according to median IMR: Group 1 (IMR  = 26), with more microvascular dysfunction. In Echo1 GLS was significantly better in Group 1 (-14.9 vs. -12.9 in Group 2, P = 0.005). However, there were no significant differences between the two groups in LV systolic volume, LVEF and WMS. Between Echo1 and Echo2, there were significant improvements in LVEF (0.48 ± 0.06 vs. 0.55 ± 0.06, P < 0.0001), GLS (-14.9 ± 1.3 vs. -17.3 ± 7.6, P = 0.001), and E/é ratio (9.3 ± 3.4 vs. 8.2 ± 2.0, P = 0.037) in Group 1, but not in Group 2: LVEF (0.49 ± 0.06 vs. 0.50 ± 0.05, P = 0.47), GLS (-12.9 ± 2.4 vs. -14.4 ± 3.2, P = 0.052), and E/é ratio (8.8 ± 2.4 vs. 10.0 ± 4.7, P = 0.18). WMSI improved significantly more in Group 1 (reduction of -17.1% vs. -6.8% in Group 2, P = 0.015). CONCLUSION: Lower IMR was associated with better myocardial GLS acutely after STEMI, and with a significantly higher recovery of the LVEF, WMSI, E/E' ratio and GLS, suggesting that IMR is an early marker of cardiac recovery, after acute myocardial infarction.info:eu-repo/semantics/publishedVersio

Endothelial dysfunction evaluated by peripheral arterial tonometry is related with peak TnI values in patients with ST elevation myocardial infarction treated with primary angioplasty

PURPOSE: The role of endothelial-dependent function in patients with acute ST elevation myocardial infarction (STEMI) is not clear. Endothelial dysfunction may contribute to the pathophysiological processes occurring after STEMI and influence the extension of myocardial necrosis. Endothelial-dependent dysfunction evaluated by peripheral arterial tonometry (PAT) has already showed to be correlated with microvascular coronary endothelial dysfunction. Our purpose was to evaluate the impact of endothelial dysfunction on peak Troponin I (TnI) values, as a surrogate for the extension of myocardial infarction, in patients with STEMI treated with primary angioplasty (P-PCI). METHODS: 58 patients with STEMI treated with P-PCI (mean age 59.0 ± 14.0 years, 46 males) were included. Endothelial function was assessed by reactive hyperaemia index (RHI) determined by PAT. Patients were divided in two groups according to the previously reported RHI threshold for high risk (1.67). The extension of myocardial necrosis was evaluated by peak TnI levels. RESULTS: RHI median value was 1.78 (IQR0.74);25 patients had endothelial dysfunction (RHI b 1.67). The two groups had no significant differences in age, gender, main risk factors and pain-to-balloon time. Patients with an RHI b 1.67 had significant larger infarcts: TnI 73.5 ng/mL (IQR 114.42 ng/mL) versus TnI 33.2 ng/mL (IQR 65.2 ng/mL); p = 0.028. On multivariate analysis, the presence of an RHI b 1.67 kept significant impact on TnI peak values (p=0.02). CONCLUSIONS: The presence of endothelial-dependent dysfunction, assessed by PAT, is related with higher peak TnI values in STEMI patients treated with P-PCI. These results strength the possibility that endothelial-dependent dysfunction may be a marker of poor prognosis and eventually a therapeutic target in patients with STEMI.info:eu-repo/semantics/publishedVersio