RESUMO
BACKGROUND: Left atrial appendage occlusion (LAAO) provides mechanical cardioembolic protection for atrial fibrillation (AF) patients who cannot use oral anticoagulation therapy (OAT). Patients with a thrombotic event despite OAT are at high risk for recurrence and may also benefit from LAAO. OBJECTIVES: This study sought to investigate the efficacy of LAAO in AF patients with a thrombotic event on OAT compared to: 1) LAAO in AF patients with a contraindication for OAT; and 2) historical data. METHODS: The international LAAO after stroke despite oral anticoagulation (STR-OAC LAAO) collaboration included patients who underwent LAAO because of thrombotic events on OAT. This cohort underwent propensity score matching and was compared to the EWOLUTION (Evaluating Real-Life Clinical Outcomes in Atrial Fibrillation Patients Receiving the WATCHMAN Left Atrial Appendage Closure Technology) registry, which represents patients who underwent LAAO because of OAT contraindications. The primary outcome was ischemic stroke. Event rates were compared between cohorts and with historical data without OAT, yielding relative risk reductions based on risk scores. RESULTS: Analysis of 438 matched pairs revealed no significant difference in the ischemic stroke rate between the STR-OAC LAAO and EWOLUTION cohorts (2.5% vs 1.9%; HR: 1.37; 95% CI: 0.72-2.61). STR-OAC LAAO patients exhibited a higher thromboembolic risk (HR: 1.71; 95% CI: 1.04-2.83) but lower bleeding risk (HR: 0.39; 95% CI: 0.18-0.88) compared to EWOLUTION patients. The mortality rate was slightly higher in EWOLUTION (4.3% vs 6.9%; log-rank P = 0.028). Relative risk reductions for ischemic stroke were 70% and 78% in STR-OAC LAAO and EWOLUTION, respectively, compared to historical data without OAT. CONCLUSIONS: LAAO in patients with a thrombotic event on OAT demonstrated comparable stroke rates to the OAT contraindicated population in EWOLUTION. The thromboembolic event rate was higher and the bleeding rate lower, reflecting the intrinsically different risk profile of both populations. Until randomized trials are available, LAAO may be considered in patients with an ischemic event on OAT.
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Anticoagulantes , Apêndice Atrial , Fibrilação Atrial , Cateterismo Cardíaco , Contraindicações de Medicamentos , AVC Isquêmico , Sistema de Registros , Humanos , Apêndice Atrial/fisiopatologia , Apêndice Atrial/diagnóstico por imagem , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/complicações , Fibrilação Atrial/mortalidade , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/terapia , Feminino , Masculino , Anticoagulantes/efeitos adversos , Anticoagulantes/administração & dosagem , Idoso , Fatores de Risco , Medição de Risco , Idoso de 80 Anos ou mais , Fatores de Tempo , Administração Oral , AVC Isquêmico/prevenção & controle , AVC Isquêmico/mortalidade , AVC Isquêmico/diagnóstico , AVC Isquêmico/etiologia , Cateterismo Cardíaco/efeitos adversos , Cateterismo Cardíaco/instrumentação , Cateterismo Cardíaco/mortalidade , Falha de Tratamento , Hemorragia/induzido quimicamente , Recidiva , Pessoa de Meia-Idade , Estudos Retrospectivos , Europa (Continente)RESUMO
INTRODUCTION: Over the last two decades, mitral transcatheter edge-to-edge repair (M-TEER) has become a safe and effective therapy for severe mitral regurgitation in patients deemed at high surgical risk. AREAS COVERED: This review aims to encompass the most relevant and updated evidence in the field of M-TEER from its inception, focusing on clinical and anatomical features for proper patient and device selection. EXPERT OPINION: Growing operator experience and device iterations have resulted in improved clinical outcomes and an expansion of the therapy to patients with complex anatomies and clinical scenarios. Future investigations are warranted to determine the best management options and the most suitable device for every patient with MR.
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Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Mitral , Humanos , Seleção de Pacientes , Insuficiência da Valva Mitral/cirurgia , Resultado do TratamentoRESUMO
INTRODUCTION: With the expanding indications of transcatheter aortic valve replacement (TAVR) to younger and low-risk patients, the life expectancy of patients currently undergoing TAVR will likely outlive the durability of transcatheter bioprosthesis. Consequently, the number of failed transcatheter bioprosthesis requiring surgical valve explant or redo TAVR is expected to increase. AREAS COVERED: The aim of this review is to provide an updated overview of redo TAVR for treating degenerated transcatheter bioprosthesis, focusing on pre-procedural planning, potential challenges of coronary reaccess during TAVR-in-TAVR and main outcomes of TAVR explant and redo TAVR. EXPERT OPINION: Patient-tailored device selection and individualized implantation height should be carefully assessed during the index TAVR procedure (weighting between pacemaker avoidance and the potential risk of coronary occlusion in future TAVR-in-TAVR). Future prospective studies comparing safety and clinical outcomes between redo TAVR vs TAVR explant are eagerly awaited.
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Estenose da Valva Aórtica , Bioprótese , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Humanos , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/métodos , Valva Aórtica/cirurgia , Bioprótese/efeitos adversos , Estenose da Valva Aórtica/cirurgia , Estudos Prospectivos , Desenho de Prótese , Resultado do Tratamento , Implante de Prótese de Valva Cardíaca/métodos , Fatores de RiscoRESUMO
Transcatheter aortic valve replacement (TAVR) is currently the treatment of choice for patients aged ≥75 years with severe aortic stenosis. Preoperative anemia is present in a large proportion of patients and may increase the risk of post-procedural complications. The purpose of this prognostic systematic review was to analyze the impact of baseline anemia on short- and mid-term outcomes following TAVR. A computerized search was performed on PubMed and Web of Science databases for studies published between January 2013 and December 2022. Primary outcomes were 30-day need for transfusion, acute renal failure, 30-day and mid-term mortality, and readmission during the first year post-TAVR. Data were analyzed via random effects model using inverse variance method with 95% confidence intervals. Eleven observational studies met our eligibility criteria and included a total of 12,588 patients. The prevalence of baseline anemia ranged between 39% and 72%, with no relevant sex differences. Patients with preprocedural anemia received more blood transfusions [OR: 2.95 (2.13-4.09)]), and exhibited increased rates of acute kidney injury [OR:1.74 (1.45-2.10)], short-term mortality [OR: 1.47 (1.07-2.01], and mid-term [OR: 1.89 (1.58-2.25)] mortality following TAVR compared with those without anemia. Baseline anemia determined an increased risk for blood transfusion, acute kidney injury, and short/mid-term mortality among TAVR recipients.
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Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Insuficiência da Valva Mitral , Humanos , Resultado do Tratamento , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/etiologia , Insuficiência da Valva Mitral/cirurgia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Impressão Tridimensional , Cateterismo Cardíaco/efeitos adversos , Falha de Prótese , Ecocardiografia TransesofagianaRESUMO
BACKGROUND: Data regarding the safety and long-term effectiveness of percutaneous closure of paravalvular leak (PVL) after transcatheter aortic valve implantation (TAVI) are scarce. AIMS: This study aims to present a large multicentre international experience of percutaneous post-TAVI PVL closure. METHODS: All patients who underwent percutaneous post-TAVI PVL closure in 14 hospitals across Europe and North America between January 2018 and October 2022 were included. RESULTS: Overall, 45 patients (64% male) were enrolled. The median age was 80 years (75-84). Among them, 67% and 33% had self-expanding and balloon-expandable valve implantations, respectively. Baseline post-TAVI PVL was severe in 67% of cases and moderate in the rest. The time from index TAVI to PVL closure procedure was 16.1 (8.7-34.8) months. Most patients were in NYHA Class III and IV (73%) before the procedure, and 40% had referred hospitalisations for heart failure between TAVI and the PVL closure procedure. Successful PVL closure was achieved in 94%, reducing regurgitation to ≤mild in 91% and moderate in the rest. The Amplatzer Valvular Plug III was the most frequently used device (27 cases), followed by the Amplatzer Valvular Plug 4. The incidence of severe adverse events was 11%. None of the patients died during the index hospitalisation. During long-term follow-up (21.7±16.2 months), the all-cause mortality rate was 14%, and patients presented improvement in functional status and a significant reduction in the rate of hospitalisation for heart failure (from 40% to 6%). CONCLUSIONS: Percutaneous PVL closure is a feasible and safe option for treating post-TAVI leaks. Successful PVL reduction to mild or less could be associated with acute and long-lasting improvements in clinical outcomes.
Assuntos
Estenose da Valva Aórtica , Insuficiência Cardíaca , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Humanos , Masculino , Idoso de 80 Anos ou mais , Feminino , Substituição da Valva Aórtica Transcateter/efeitos adversos , Próteses Valvulares Cardíacas/efeitos adversos , Resultado do Tratamento , Implante de Prótese de Valva Cardíaca/métodos , Sistema de Registros , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgiaRESUMO
INTRODUCTION AND OBJECTIVES: The cusp overlap technique (COT) has been proposed to reduce conduction disturbances (CD) after transcatheter aortic valve implantation (TAVI) with self-expanding supra-annular devices, but there are scarce data on COT with intra-annular valves. The aim of this study was to determine whether the use of the COT during Portico implantation results in higher valve implantation and lower rates of CD. METHODS: We included 85 patients undergoing TAVI with the Portico FlexNav system: 43 retrospective patients using the standard 3-cusp view and 42 prospective patients with the COT. Primary endpoints were implantation depth and new-onset CD (composite outcome of new-onset left bundle branch block and new permanent pacemaker implantation). RESULTS: COT resulted in a higher implantation depth (noncoronary cusp: 4.9±3.9 vs 7.4±3.0; P=.005) and lower new-onset CD (31.0% vs 58.1%; P=.012), with a tendency toward a lower need for permanent pacemaker implantation (14.3% vs 30.2%, P=.078; 7.7% vs 31.0%; P=.011 in patients without pre-existing right bundle branch block). Transvalvular aortic gradients were slightly lower with COT (8.7±3.7 vs 11.0±6.1; P=.044). There were no differences in technical success or major procedure-related complications. On multivariate analysis, COT use was associated with a lower risk of new-onset CD. CONCLUSIONS: Use of the COT during Portico implantation is feasible and facilitates a higher valve implant, which in turn may help to reduce rates of new-onset CD.
Assuntos
Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Marca-Passo Artificial , Substituição da Valva Aórtica Transcateter , Humanos , Substituição da Valva Aórtica Transcateter/métodos , Estudos Retrospectivos , Estudos Prospectivos , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/cirurgia , Resultado do Tratamento , Doença do Sistema de Condução Cardíaco , Bloqueio de Ramo/diagnóstico , Bloqueio de Ramo/terapia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgiaAssuntos
Estenose da Valva Aórtica , Bioprótese , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Humanos , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Resultado do Tratamento , Substituição da Valva Aórtica Transcateter/efeitos adversos , Implante de Prótese de Valva Cardíaca/efeitos adversos , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Desenho de PróteseRESUMO
INTRODUCTION AND OBJECTIVES: The PASCAL system is a novel device for transcatheter mitral valve repair based on the edge-to-edge concept. The unique features of this device might have a relevant impact on the repair outcomes. There are few data on clinical outcomes in real-life registries. The aim of this study was to report the early Iberian experience (Spain and Portugal) of the PASCAL system. METHODS: Procedural and 30-day outcomes were investigated in consecutive patients with symptomatic severe mitral regurgitation (MR) treated with the PASCAL system at 10 centers. Primary efficacy endpoints were technical success and degree of residual MR at discharge. The primary safety endpoint was the rate of major adverse events (MAE) at 30 days. RESULTS: We included 68 patients (age, 75 [68-81] years; 38% women; EuroSCORE II 4.5%). MR etiology was degenerative in 25%, functional in 65%, and mixed in 10%. A total of 71% of patients were in New York Heart Association (NYHA) functional class≥III. Technical success was achieved in 96% and independent capture was used in 73% of procedures. In the treated population, MR at discharge was≤2+ in 100%, with no in-hospital deaths. At 30 days, the MAE rate was 5.9%, the all-cause mortality rate was 1.6%, 98% were in NYHA functional class≤II, and 95% had MR≤2+ (P<.001). CONCLUSIONS: Transcatheter mitral valve repair with the PASCAL system was safe and effective, with high procedural success and low rates of MAE. At 30 days, MR was significantly reduced, with a significant improvement in functional status.
Assuntos
Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Mitral , Humanos , Feminino , Idoso , Masculino , Insuficiência da Valva Mitral/diagnóstico , Insuficiência da Valva Mitral/cirurgia , Valva Mitral/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Cateterismo Cardíaco/efeitos adversos , Resultado do TratamentoRESUMO
INTRODUCTION AND OBJECTIVES: Transthyretin cardiac amyloidosis (ATTR-CA) patients often have atrial fibrillation and increased bleeding/thrombogenic risks. We aimed to evaluate outcomes of left atrial appendage closure (LAAC) compared with patients without a known diagnosis of CA. METHODS: Comparison at long-term of patients diagnosed with ATTR-CA who underwent LAAC between 2009 and 2020 and those without a known diagnosis of CA. RESULTS: We studied a total of 1159 patients. Forty patients (3.5%) were diagnosed with ATTR-CA; these patients were older and had more comorbidities, higher HAS-BLED and CHA2DS2-VASc scores, and lower left ventricular function. Successful LAAC was achieved in 1137 patients (98.1%) with no differences between groups. Regarding in-hospital and follow-up complications, there were no differences between the groups in ischemic stroke (5% vs 2.5% in those without a known diagnosis of CA; P=.283), hemorrhagic stroke (2.5% and 0.8% in the control group; P=.284), major or minor bleeding. At the 2-year follow-up, there were no significant differences in mortality (ATTR-CA: 20% vs those without known CA: 13.6%, 0.248); however, the at 5-year follow-up, ATTR-CA patients had higher mortality (40% vs 19.2%; P <.001) but this difference was unrelated to hemorrhagic complications or ischemic stroke. CONCLUSIONS: LAAC could reduce the risk of bleeding complications and ischemic cerebrovascular events without increasing the rate of early or mid-term complications. Although long-term survival was impaired in ATTR-CA patients, it was comparable to that of patients without a known diagnosis of CA at the 2-year follow-up, suggesting that LAAC for patients with ATTR-CA might not be futile.
Assuntos
Amiloidose , Apêndice Atrial , Fibrilação Atrial , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Hemorragia/complicações , Fibrilação Atrial/complicações , Fibrilação Atrial/cirurgia , Fibrilação Atrial/diagnóstico , Amiloidose/complicações , Amiloidose/diagnóstico , Resultado do TratamentoAssuntos
Estenose da Valva Aórtica , Valvuloplastia com Balão , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Valvuloplastia com Balão/efeitos adversos , Humanos , Desenho de Prótese , Fatores de Risco , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do TratamentoRESUMO
Sinus contrast material retention after transcatheter aortic valve replacement (TAVR) is a rare phenomenon that may reflect an increased risk for thrombotic complications. We present 3 cases of persistent contrast agent retention in the sinus of Valsalva during the TAVR procedure that portend the occurrence of embolic stroke or bioprosthetic valve thrombosis. (Level of Difficulty: Advanced.).
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An 80-year-old woman with mitral valve repair failure was admitted with hemolytic anemia secondary to the impact of a regurgitant jet on the annuloplasty ring. Transcatheter repair to treat both mitral regurgitation and hemolysis was favored because of surgical risk. Transcatheter edge-to-edge repair represents an alternative for treating hemolysis associated with mitral regurgitation. (Level of Difficulty: Advanced.).
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BACKGROUND: Cardiac computed tomography angiography (CCTA) appears to be an appropriate imaging technique for device surveillance after left atrial appendage occlusion (LAAO). However, the available experience is limited. AIMS: The aim of this study was to determine the prevalence, mechanisms and clinical impact of left atrial appendage (LAA) patency and device-related thrombosis (DRT) following LAAO utilising a novel CCTA-based classification. METHODS: Consecutively enrolled patients who underwent LAAO with an AMPLATZER device were followed up with CCTA. Mechanisms and frequency of residual patency were evaluated and correlated with clinical events. Atrial-side device thrombus, device positioning and presence of signs of device stability were also analysed. RESULTS: A total of 137 patients were included. LAA patency was observed in 56.9% (n=78). Mechanisms and frequency of patency were: malapposition of proximal segment of the device lobe (55.1%), peri-device leak (PDL, 34.6%) and fabric permeability (5.8%). Lobe-LAA axis misalignment was the only independent predictor of device patency after LAAO (HR 38.3, 95% CI: 13.6-107.0; p<0.001). After a median follow-up of 638 days, patency was not associated with an increased risk of death (all-cause or cardiovascular death) or cerebral/peripheral embolism regardless of its mechanism. Any degree of hypo-attenuated thickening (HAT) was found in 16.8% (n=23) of patients, of whom 16 (11.7%) had low-grade HAT and 7 (5.1%) had high-grade HAT or definite DRT. Complete sealing was associated with increased rates of low-grade HAT. CONCLUSIONS: LAA patency on CCTA follow-up is a frequent phenomenon due to malapposition of the proximal segment of the device lobe, PDL or fabric permeability. Patency was not associated with adverse outcomes. Low-grade HAT may be related to a benign, uneventful, endothelialisation process favoured by complete LAAO.
Assuntos
Apêndice Atrial , Fibrilação Atrial , Dispositivo para Oclusão Septal , Trombose , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/epidemiologia , Ecocardiografia Transesofagiana , Humanos , Prevalência , Dispositivo para Oclusão Septal/efeitos adversos , Trombose/diagnóstico por imagem , Trombose/epidemiologia , Trombose/etiologia , Tomografia Computadorizada por Raios X , Resultado do TratamentoAssuntos
Dispositivos de Terapia de Ressincronização Cardíaca/efeitos adversos , Ecocardiografia Transesofagiana/métodos , Fluoroscopia/métodos , Implante de Prótese de Valva Cardíaca , Complicações Intraoperatórias , Insuficiência da Valva Tricúspide , Idoso , Fibrilação Atrial/complicações , Fibrilação Atrial/terapia , Cateterismo Cardíaco/instrumentação , Cateterismo Cardíaco/métodos , Feminino , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/instrumentação , Implante de Prótese de Valva Cardíaca/métodos , Humanos , Imageamento Tridimensional/métodos , Cuidados Intraoperatórios/métodos , Complicações Intraoperatórias/diagnóstico por imagem , Complicações Intraoperatórias/etiologia , Resultado do Tratamento , Insuficiência da Valva Tricúspide/complicações , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/fisiopatologia , Insuficiência da Valva Tricúspide/cirurgiaRESUMO
BACKGROUND AND AIM: Recent randomized data comparing percutaneous mitral valve repair (PMVR) versus optimal medical treatment in patients with functional MR (FMR) seemed to highlight the importance of the learning curve not only for procedural outcomes but also for patient selection. The aim of the study was to compare a contemporary series of patients undergoing PMVR using a second-generation Mitraclip device (Mitraclip NT) with previous cohorts treated with a first-generation system. METHODS: This multicenter study collected individual data from 18 centers between 2012 and 2017. The cohort was divided into three groups according to the use of the first-generation Mitraclip during the first (control-1) or second half (control-2) or the Mitraclip NT system. RESULTS: A total of 545 consecutive patients were included in the study. Among all, 182 (33.3%), 183 (33.3%), and 180 (33.3%) patients underwent mitral repair in the control-1, control-2, and NT cohorts, respectively. Procedural success was achieved in 93.3% of patients without differences between groups. Major adverse events did not statistically differ among groups, but there was a higher rate of pericardial effusion in the control-1 group (4.3%, 0.6%, and 2.6%, respectively; p = 0.025). The composite endpoint of death, surgery, and admission for congestive heart failure (CHF) at 12 months was lower in the NT group (23.5% in control-1, 22.5% in control-2, and 8.3% in the NT group; p = 0.032). CONCLUSIONS: The present paper shows that contemporary clinical outcomes of patients undergoing PMVR with the Mitraclip system have improved over time.
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BACKGROUND: Left atrial appendage occlusion (LAAO) is an accepted strategy for cardioembolic events prevention in patients with non-valvular atrial fibrillation (AF) unsuitable for anticoagulation. However, uncertainties persist regarding the benefit of LAAO in highly-comorbid patients. The aim of this study was to assess the impact of the CHA2DS2-VASc score beyond thromboembolic risk in predicting clinical outcomes in patients undergoing LAAO. METHODS: 160 patients who underwent LAAO were included and categorized into two groups according to their stroke risk (89 with CHA2DS2-VASc >4 vs. 71 with lower risk). The coprimary endpoints were death and stroke at follow-up. Thromboembolic and bleeding events were compared to those predicted from CHA2DS2-VASc and HAS-BLED scores. RESULTS: Over a median follow-up of 679 days, CHA2DS2-VASc >4 was associated with increased all-cause mortality compared with patients with lower thromboembolic risk (HR: 3.23; 95% CI: 1.28-8.19; p < 0.001). However, the rates of stroke after LAAO were not significantly different between risk groups. The observed annual rates of stroke and major bleeding were lower than predicted. CONCLUSIONS: Despite increased long-term mortality in patients with CHA2DS2-VASc >4, LAAO remains beneficial in reducing stroke and bleeding events in high-risk AF patients unsuitable for anticoagulation.
Assuntos
Apêndice Atrial , Anticoagulantes , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Humanos , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Tromboembolia/epidemiologia , Tromboembolia/etiologia , Tromboembolia/prevenção & controleRESUMO
BACKGROUND: Atrial coronary branch occlusion is a hardly recognizable clinical entity that can promote atrial fibrillation. The low diagnostic accuracy of the ECG could deal with the characteristics of the ischemia-induced changes in local atrial electrograms, but these have not been described. OBJECTIVES: We analyzed the effects of selective acute atrial branch occlusion on local myocardial structure, atrial electrograms, and surface ECG in an experimental model close to human cardiac anatomy and electrophysiology. METHODS: Six anesthetized open-chest anesthetized pigs underwent surgical occlusion of an atrial coronary branch arising from the right coronary artery during 4 h. Atrial electrograms and ECG were simultaneously recorded. One additional pig acted as sham control. In all cases, the hearts were processed for anatomopathological analysis. RESULTS: Atrial branch occlusion induced patchy atrial necrosis with sharp border zone. During the first 30 min of occlusion, atrial electrograms showed progressive R wave enlargement (1.8 ± 0.6 mV vs. 2.5 ± 1.1 mV, p < 0.01), delayed local activation times (28.5 ± 8.9 ms vs. 36.1 ± 16.4 ms, p < 0.01), ST segment elevation (-0.3 ± 0.3 mV vs. 1.0 ± 1.0 mV, p < 0.01), and presence of monophasic potentials. Atrial ST segment elevation decreased after 2 h of occlusion. The electrical border zone was â¼1 mm and expanded over time. After 2 h of occlusion, the ECG showed a decrease in P wave amplitude (from 0.09 ± 0.04 mV to 0.05 ± 0.04 mV after 165 min occlusion, p < 0.05) and duration (64.4 ± 8.0 ms vs. 80.9 ± 12.6 ms, p < 0.01). CONCLUSION: Selective atrial branch occlusion induces patchy atrial infarction and characteristic changes in atrial activation, R/S wave, and ST segment that are not discernible at the ECG. Only indirect changes in P wave amplitude and duration were appreciated in advanced stages of acute coronary occlusion.