Gene therapy for refractory angina and cell therapy for heart failure: experience of a Brazilian research group.

Cell therapy has shown impressive effects in experimental cardiomyopathy models. To a lesser extent, gene therapy has also been studied. In both cases, translation to clinical therapy has been disappointing. This paper is intended to describe the experience and achievements of a multicenter working group located in Porto Alegre, southern Brazil, in experimental and translational research projects for cell-based and gene therapy methods in the treatment of dilated and ischemic cardiomyopathies. The results of preclinical and clinical studies showed that bone marrow mononuclear stem cells indeed have an effect in improving myocardial perfusion and contractile function, but the overall results are poorly translated to the clinical level. Gene therapy studies with direct myocardial injections of naked VEGF 165 plasmid showed improvement in myocardial perfusion and function in animal models. A randomized clinical trial found that this method is safe and improved myocardial perfusion, but the benefits disappeared after 1 year. An animal experiment associating VEGF 165 with angiopoietin was undertaken in mini pigs to extend the durability of that therapy. In conclusion, our efforts to better understand the mechanisms and functions of gene and cell-based therapies in cardiology resulted in significant findings and propose a future look at cell-free therapeutic approaches.

VEGF gene therapy cooperatively recruits molecules from the immune system and stimulates cell homing and angiogenesis in refractory angina.

BACKGROUND: New vessels are formed in response to stimuli from angiogenic factors, a process in which paracrine signaling is fundamental. OBJECTIVE: To investigate the cooperative paracrine signaling profile in response to Vascular Endothelial Growth Factor (VEGF) gene therapy in patients with coronary artery disease (CAD) and refractory angina. METHOD: A cohort study was conducted in which plasma was collected from patients who underwent gene therapy with a plasmid expressing VEGF 165 (10) and from surgical procedure controls (4). Blood samples were collected from both groups prior to baseline and on days 3, 9 and 27 after the interventions and subjected to systemic analysis of protein expression (Interleukin-6, IL-6; Tumor Necrosis Factor-α, TNF-α; Interleukin-10, IL-10; Stromal Derived Factor-1 α, SDF-1α; VEGF; Angiopoietin-1, ANGPT-1; and Endothelin-1, ET-1) using the enzyme-linked immunosorbent assay (ELISA). RESULTS: Analysis showed an increase in proinflammatory IL-6 (p=0.02) and ET-1 (p=0.05) on day 3 after gene therapy and in VEGF (p=0.02) on day 9. A strong positive correlation was found between mobilization of endothelial progenitor cells and TNF-α on day 9 (r=0.71; p=0.03). Furthermore, a strong correlation between ß-blockers, antiplatelets, and vasodilators with SDF-1α baseline in the group undergoing gene therapy was verified (r=0.74; p=0.004). CONCLUSION: Analysis of cooperative paracrine signaling after VEGF gene therapy suggests that the immune system cell and angiogenic molecule expression as well as the endothelial progenitor cell mobilization are time-dependent, influenced by chronic inflammatory process and continuous pharmacological treatment.

High doses of vascular endothelial growth factor 165 safely, but transiently, improve myocardial perfusion in no-option ischemic disease.

UNLABELLED: Gene therapy can induce angiogenesis in ischemic tissues. The aim of this study was to assess safety, feasibility, and results, both clinical and on myocardial perfusion, of gene therapy in refractory angina. This was a phase I/II, prospective, temporal-controlled series, clinical trial. Thirteen patients were maintained for minimum 6 months under optimized clinical management, and then received intramyocardial injections of 2000 µg plasmid vascular endothelial growth factor 165 and were followed by single-photon emission computed tomography (SPECT), treadmill tests, Minnesota quality of life questionnaire (QOL), and New York Heart Association (NYHA) functional plus Canadian Cardiovascular Society (CCS) angina classifications. There were no deaths, early or late. During the optimized clinical treatment, we observed worsening of rest ischemia scores on SPECT (p<0.05). After treatment, there was a transitory increase in myocardial perfusion at the third-month SPECT under stress (pre-operative [pre-op] 18.38 ± 7.51 vs. 3 months 15.31 ± 7.30; p<0.01) and at the sixth month under rest (pre-op 13.23 ± 7.98 vs. 6 months: 16.92 ± 7.27; p<0.01). One year after, there were improvements in treadmill test steps (pre-op 2.46 ± 2.07 vs.12 months 4.15 ± 2.23; p<0.01) and oxygen consumption (pre-op 7.66 ± 4.47 vs.12 months 10.89 ± 4.65; p<0.05), QOL (pre-op 48.23 ± 18.35 vs.12 months 28.31 ± 18.14; p<0.01) scores, and CCS (pre-op 3 [3-3.5] vs.12 months 2 [1-2.5]; p<0.01) and NYHA (pre-op 3 [3-3] vs. 2 [2-2] vs. 12 months 2 [1-2]; p<0.01) classes. Gene therapy demonstrated to be feasible and safe in this advanced ischemic cardiomyopathy patient sample. There were improvements in clinical evaluation parameters, and a transitory increase in myocardial perfusion detectable by SPECT scintigraphy. CLINICAL TRIAL REGISTRATION: NCT00744315 http://clinicaltrials.gov/

Terapia gênica com fator de crescimento endotelial vascular 165 para pacientes com angina refratária: mobilização de células progenitoras endoteliais / VEGF 165 gene therapy for patients with refractory angina: mobilization of endothelial progenitor cells

FUNDAMENTO: O fator de crescimento endotelial vascular (VEGF - vascular endothelial growth factor) induz a mobilização de células progenitoras endoteliais (CPEs) com capacidade de proliferação e diferenciação em células endoteliais, contribuindo, dessa forma, para o processo angiogênico. OBJETIVO: Buscamos avaliar o comportamento de CPEs em pacientes com doença cardíaca isquêmica e angina refratária que receberam injeções intramiocardicas de 2000 µg de VEGF165 como terapia única. MÉTODOS: O estudo foi uma subanálise de um ensaio clínico. Pacientes com doença cardíaca isquêmica avançada e angina refratária foram avaliados para inclusão no estudo. Os critérios de inclusão foram: sinais e sintomas de angina e/ou insuficiência cardíaca apesar de tratamento medicamentoso máximo e área de isquemia miocárdica de, no mínimo, 5% conforme avaliado por uma tomografia computadorizada por emissão de fóton único (TCEFU). Os critérios de exclusão foram: idade > 65 anos, fração de ejeção do ventrículo esquerdo < 25% e cancer diagnosticado. Os pacientes cujos níveis de CPE foram avaliados foram incluídos. A intervenção consistiu na administração de 2000 µg de VEGF 165 de plasmídeo injetado no miocárdio isquêmico. A frequência de células CD34+/KDR+ foi analisada por citometria de fluxo antes e 3, 9, e 27 dias após a intervenção. RESULTADOS: Um total de 9 pacientes foram incluídos, 8 homens, média de idade de 59,4 anos, fração de ejeção ventricular esquerda de 59,3%, e classe de angina predominante III. Observou-se um aumento significativo dos níveis de CPEs no terceiro dia após a intervenção. Todavia, 9 e 27 dias após a intervenção, os níveis de CPEs foram similares aos basais. CONCLUSÃO: Identificamos uma mobilização transitória de CPE, com pico no terceiro dia após a intervenção com VEGF 165 em pacientes com angina refratária. Todavia, os níveis de CPEs apresentaram-se semelhantes aos basais 9 e 27 dias após a intervenção.

BACKGROUND: Vascular endothelial growth factor (VEGF) induces mobilization of endothelial progenitor cells (EPCs) with the capacity for proliferation and differentiation into mature endothelial cells, thus contributing to the angiogenic process. OBJECTIVE: We sought to assess the behavior of EPCs in patients with ischemic heart disease and refractory angina who received an intramyocardial injections of 2000 µg of VEGF 165 as the sole therapy. METHODS: The study was a subanalysis of a clinical trial. Patients with advanced ischemic heart disease and refractory angina were assessed for eligibility. Inclusion criteria were as follows: signs and symptoms of angina and/or heart failure despite maximum medical treatment and a myocardial ischemic area of at least 5% as assessed by single-photon emission computed tomography (SPECT). Exclusion criteria were as follows: age > 65 years, left ventricular ejection fraction < 25%, and a diagnosis of cancer. Patients whose EPC levels were assessed were included. The intervention was 2000 µg of VEGF 165 plasmid injected into the ischemic myocardium. The frequency of CD34+/KDR+ cells was analyzed by flow cytometry before and 3, 9, and 27 days after the intervention. RESULTS: A total of 9 patients were included, 8 males, mean age 59.4 years, mean left ventricular ejection fraction of 59.3% and predominant class III angina. The number of EPCs on day 3 was significantly higher than that at baseline (p = 0.03); however, that on days 9 and 27 was comparable to that at baseline. CONCLUSION: We identified a transient mobilization of EPCs, which peaked on the 3th day after VEGF 165 gene therapy in patients with refractory angina and returned to near baseline levels on days 9 and 27.

VEGF 165 gene therapy for patients with refractory angina: mobilization of endothelial progenitor cells.

BACKGROUND: Vascular endothelial growth factor (VEGF) induces mobilization of endothelial progenitor cells (EPCs) with the capacity for proliferation and differentiation into mature endothelial cells, thus contributing to the angiogenic process. OBJECTIVE: We sought to assess the behavior of EPCs in patients with ischemic heart disease and refractory angina who received an intramyocardial injections of 2000 µg of VEGF 165 as the sole therapy. METHODS: The study was a subanalysis of a clinical trial. Patients with advanced ischemic heart disease and refractory angina were assessed for eligibility. Inclusion criteria were as follows: signs and symptoms of angina and/or heart failure despite maximum medical treatment and a myocardial ischemic area of at least 5% as assessed by single-photon emission computed tomography (SPECT). Exclusion criteria were as follows: age > 65 years, left ventricular ejection fraction < 25%, and a diagnosis of cancer. Patients whose EPC levels were assessed were included. The intervention was 2000 µg of VEGF 165 plasmid injected into the ischemic myocardium. The frequency of CD34+/KDR+ cells was analyzed by flow cytometry before and 3, 9, and 27 days after the intervention. RESULTS: A total of 9 patients were included, 8 males, mean age 59.4 years, mean left ventricular ejection fraction of 59.3% and predominant class III angina. The number of EPCs on day 3 was significantly higher than that at baseline (p = 0.03); however, that on days 9 and 27 was comparable to that at baseline. CONCLUSION: We identified a transient mobilization of EPCs, which peaked on the 3th day after VEGF 165 gene therapy in patients with refractory angina and returned to near baseline levels on days 9 and 27.

Terapia gênica para cardiopatia isquêmica: revisão de ensaios clínicos / Gene therapy for ischemic heart disease: review of clinical trials

Cardiopatia isquêmica grave com angina refratária a formas convencionais de tratamento apresenta-se em uma crescente incidência. Para tratar angina refratária, terapias alternativas na tentativa de redução da isquemia miocárdica e alívio de sintomas têm sido estudadas. Neste contexto, a terapia gênica representa uma opção, pela possibilidade de induzir angiogênese, estabelecer circulação colateral e reperfundir miocárdio isquêmico. Diversos ensaios clínicos têm sido conduzidos e, com exceção de casos isolados e específicos de efeitos adversos, há indicação de segurança, viabilidade e potencial eficácia da terapia. O benefício clínico não está bem definido. Neste artigo, revisamos os ensaios clínicos que utilizaram terapia gênica para tratamento de pacientes cardiopatas isquêmicos. A abordagem inclui: (1) isquemia miocárdica e angiogênese, sobre os aspectos fisiopatológicos envolvidos; (2) fatores de crescimento, tratando sobre aspectos específicos e justificando a utilização em pacientes cardiopatas isquêmicos sem opções pela terapêutica convencional; (3) ensaios clínicos controlados, onde é apresentado um resumo dos principais estudos envolvendo terapia gênica para tratamento da cardiopatia isquêmica grave; (4) nossa experiência, especialmente sobre resultados preliminares do primeiro ensaio clínico de terapia gênica do Brasil e (5) perspectivas.

Severe ischemic heart disease with refractory angina, occurs in increasing incidence. Alternative forms of treatment, in an attempt to reduce myocardial ischemia and relief of symptoms has been studied. In this context, gene therapy is an option, for the possibility of inducing angiogenesis, establish collateral circulation and reperfuse ischemic myocardium. Several clinical trials have been conducted and, except for specific cases of adverse effects, there is indication of safety, feasibility and potential effectiveness of therapy. The clinical benefit, however, is not yet well established. In this article we review the clinical trials of gene therapy for patients with ischemic heart disease. The approach includes: (1) myocardial ischemia and angiogenesis on the pathophysiological aspects involved, (2) growth factors, dealing with specific aspects and justifying the use in cardiac patients with no option for conventional therapy, (3) controlled clinical trials, where a summary of the main studies involving gene therapy for severe ischemic heart disease is presented, (4) our experience, especially on preliminary results of the first gene therapy clinical trial in Brazil and (5) future prospects.

Implante valvular aórtico percutâneo (IVAP): análise de uma série de casos realizados com o dispositivo autoexpansível CoreValveTM sem uso de pré-dilatação / Percutaneous aortic valve implantation )PAVI): analysis of a series of cases usinf the CoreValveTM self-expandable device without pre-dilation

Introdução: O implante valvular aórtico percutâneo (IVAP) vem se desenvolvendo rapidamente nos últimos anos. A manipulação da valva aórtica degenerada pode acarretar complicações. O IVAP direto, sem pré-dilatação com balão e com menor manipulação, seria uma alternativa. O objetivo deste estudo é apresentar uma série de 8 casos de IVAP direto com seguimento a médio prazo realizado no Instituto de Cardiologia do Rio Grande do Sul. Métodos: Série de 8 casos com descrição da técnica e resultados imediatos e a médio prazo do implante do dispositivo CoreValveTM sem valvuloplastia com balão. Resultados: No total, 7 pacientes do sexo masculino e 1 do sexo feminino, com média de idade de 76 anos e EuroSCORE logístico variando de 6 a 62, foram submetidos ao implante do dispositivo CoreValveTM. Houve significativa queda dos gradientes entre o ventrículo esquerdo e a aorta. Foram registrados três casos de insucesso do implante, um óbito no período pós-implante imediato e um óbito aos 6 meses, sem relação com o procedimento. No seguimento de um ano, não houve novos casos de implante de marca-passo e eventos embólicos. Conclusões: O IVAP direto sem pré-dilatação com balão mostrou-se uma alternativa potencialmente eficaz. Quando realizado com sucesso, determina melhora dos sintomas, diminuição sustentável do gradiente transvalvar aórtico e aumento da área valvar aórtica. Não está claro, contudo, qual o paciente e qual a condição anatômica ideal para essa abordagem. Estudos adicionais e seguimento mais prolongado ainda são necessários para definir o exato papel e as precisas indicações dessa variação da técnica.

Implante valvular aórtico percutâneo: dois anos de evolução da experiência inicial no sul do Brasil / Transcatheter aortic valve implantation: two-year follow-up of the initial southern Brazilian experience

Introdução: A estenose aórtica é uma afecção prevalente e com altas taxas de morbidade e mortalidade, sendo atroca valvular cirúrgica a abordagem clássica. Indivíduos idosos e com outras comorbidades apresentam elevadorisco operatório. O implante valvular aórtico percutâneo surge como alternativa à cirurgia padrão. O objetivo deste estudo é apresentar o seguimento de dois anos dos primeiros casos realizados no Sul do Brasil com essa abordagem inédita. Métodos: Série de casos com descrição da técnica e resultados imediatos e a médio prazo do implante do dispositivo CoreValveTM (Medtronic Inc., Minneapolis, EstadosUnidos), que consiste de uma bioprótese de pericárdio porcino montada em stent auto expansível de nitinol, introduzido pela via arterial. Resultados: Foram submetidos ao implante desse dispositivo quatro pacientes do sexo feminino, com idade variando entre 81 anos e 90 anos e EuroSCORE logístico de 20% a 36%. Observou-se significativa queda do gradiente ventrículo esquerdo-aorta, assim como ausência de complicações cardiovasculares maiores, embora duas pacientes tenham necessitado de implante de marca-passo definitivo por distúrbio de condução atrioventricular.No seguimento de dois anos observou-se melhora da classe funcional e manutenção dos gradientes e das áreas valvares aórticas alcançadas no final do procedimentoe diminuição progressiva da massa ventricular esquerda. Conclusões: Esta experiência inicial com implante valvularaórtico percutâneo tem se mostrando segura e efetiva em análise a médio prazo. Estudos com seguimento a longoprazo são necessários para definir o exato papel e precisas indicações dessa nova e promissora técnica.

Background: Aortic stenosis is a prevalent disease with high morbidity and mortality, whose classical approach is surgical valve replacement. Elderly patients and those with other comorbidities present high surgical risk. Transcatheter aortic valve implantation is an effective alternative to standardsurgery. The objective of this study is to report the 2-year follow-up of the first cases performed in Southern Brazil.Methods: Series of cases describing the technique, immediate and medium term results of the CoreValveTM (Medtronic Inc., Minneapolis, USA) device implantation, a porcine pericardialbioprosthesis mounted on a self expanding nitinol stent, delivered via transarterial access. Results: Four female patients, with ages ranging from 81 to 90 years and a logistic EuroSCORE ranging from 20% to 36% were successfully submitted to the implantation of this device. A significantreduction in the left ventricle-aortic gradient, and no major cardiovascular complications were observed, although2 patients required the implantation of a permanent pacemaker due to complete atrioventricular block. Improvementof functional class and maintenance of gradients and aortic valve areas obtained at the end of the procedure,as well as a progressive decrease of left ventricular mass were observed in the 2 year follow-up. Conclusions: Thisearly experience with the CoreValveTM transcatheter aortic valve implantation has proved to be safe and effective in the medium term outcome. Long-term follow-up studies are required to define the exact role and adequate indicationsfor this new and promising technology.

Gene therapy for ischemic heart disease: review of clinical trials.

Severe ischemic heart disease with refractory angina, occurs in increasing incidence. Alternative forms of treatment, in an attempt to reduce myocardial ischemia and relief of symptoms has been studied. In this context, gene therapy is an option, for the possibility of inducing angiogenesis, establish collateral circulation and reperfuse ischemic myocardium. Several clinical trials have been conducted and, except for specific cases of adverse effects, there is indication of safety, feasibility and potential effectiveness of therapy. The clinical benefit, however, is not yet well established. In this article we review the clinical trials of gene therapy for patients with ischemic heart disease. The approach includes: (1) myocardial ischemia and angiogenesis on the pathophysiological aspects involved, (2) growth factors, dealing with specific aspects and justifying the use in cardiac patients with no option for conventional therapy, (3) controlled clinical trials, where a summary of the main studies involving gene therapy for severe ischemic heart disease is presented, (4) our experience, especially on preliminary results of the first gene therapy clinical trial in Brazil and (5) future prospects.

VEGF gene therapy for angiogenesis in refractory angina: phase I/II clinical trial.

OBJECTIVE: Safety, feasibility and early myocardial angiogenic effects evaluation of transthoracic intramyocardial phVEGF165 administration for refractory angina in no option patients. METHODS: Cohort study, in which 13 patients with refractory angina under optimized clinical treatment where included, after cineangiograms had been evaluated and found unfeasible by surgeon and interventional cardiologist. Intramyocardial injections of 5 mL solution containing plasmidial VEGF165 where done over the ischemic area of myocardium identified by previous SPECT/Sestamibi scan. Evaluations included a SPECT scan, stress test, Minnesota QOL questionnaire and NYHA functional class and CCS angina class determinations. RESULTS: There were no deaths or new interventions during the study period. There were no significant variations in SPECT scans, QOL scores and stress tests results during medical treatment in the included patients. After the 3rd post operative month, there was improvement in SPECT segmental scores, SSS (18.38 ± 7.51 vs. 15.31 ± 7.29, P = 0.003) and SRS (11.92 ± 7.49 vs. 8.53 ± 6.68, P = 0.002). The ischemic area extension, however, had non-significant variation (23.38 ± 13.12% vs. 20.08 ± 13.88%, P = 0.1). Stress tests METs varied from 7.66 ± 4.47 pre to 10.29 ± 4.36 METs post-op (P = 0.08). QOL score improved from 48.23 ± 18.35 pre to 30.15 ± 20.13 post-op points (P = 0.02). NYHA class was 3.15 ± 0.38 pre vs. 1.77 ± 0.83 post-op (P = 0.001) and angina CCS class, 3.08 ± 0.64 vs. 1.77 ± 0.83 (P = 0.001). CONCLUSIONS: Intramyocardial VEGF165 therapy for refractory angina, in this small trial of no option patients, resulted feasible and safe. Early clinical and scintilographic data showed improvements in symptoms and myocardial perfusion, with regression of ischemia severity in treated areas.

Terapia gênica com VEGF para angiogênese na angina refratária: ensaio clínico fase I/II / VEGF gene therapy for angiogenesis in refractory angina: phase I/II clinical trial

OBJETIVO: Avaliar a segurança, viabilidade e efeitos iniciais, clínicos e sobre a perfusão miocárdica, da administração intramiocárdica, transtorácica, de VEGF 165 plasmidial em pacientes com doença arterial coronariana avançada e angina refratária, não passíveis de revascularização percutânea e cirúrgica. MÉTODOS: Ensaio clínico fase I/II. Treze pacientes cardiopatas isquêmicos com angina refratária apesar de tratamento medicamentoso máximo por no mínimo seis meses, não passíveis de revascularização cirúrgica ou por cateter foram submetidos a injeções intramiocárdicas de 2000µg VEGF 165 plasmidial. Os pacientes foram avaliados por cintilografia miocárdica, teste ergométrico, questionário de qualidade de vida (Minnesota) e determinação das classes de insuficiência cardíaca (NYHA) e angina (CCS). RESULTADOS: Não houve óbitos ou reintervenções. Durante o período de tratamento medicamentoso máximo, não se observou diferenças em cintilografias miocárdicas, testes ergométricos e questionários de qualidade de vida, ainda, houve tendência a piora das classes NYHA (P=0,05) e CCS (P=0,05). Três meses após intervenção, observou-se melhora dos escores cintilográficos SSS (18,38±7,51 vs. 15,31±7,29, P=0,003) e SRS (11,92±7,49 vs. 8,53±6,68, P=0,002), porém não na proporção da extensão da área de miocárdio isquêmico (23,38±13,12 por cento vs. 20,08±13,88 por cento, P=0,1). Houve tendência a melhora dos METs nas ergometrias (7,66±4,47 vs. 10,29±4,36, P=0,08), melhora do escore de qualidade de vida (48,23±18,35 vs. 30,15±20,13; P=0,02) e das classes NYHA (3,15±0,38 vs. 1,77±0,83, P=0,001) e CCS (3,08±0,64 vs. 1,77±0,83, P=0,001), no mesmo período. CONCLUSÕES: A terapia demonstrou-se segura e viável nesta série de pacientes. Os resultados iniciais tendem a demonstrar melhora na gravidade da angina e redução da intensidade da isquemia miocárdica.

OBJECTIVE: Safety, feasibility and early myocardial angiogenic effects evaluation of transthoracic intramyocardial phVEGF165 administration for refractory angina in no option patients. METHODS: Cohort study, in which 13 patients with refractory angina under optimized clinical treatment where included, after cineangiograms had been evaluated and found unfeasible by surgeon and interventional cardiologist. Intramyocardial injections of 5mL solution containing plasmidial VEGF165 where done over the ischemic area of myocardium identified by previous SPECT/Sestamibi scan. Evaluations included a SPECT scan, stress test, Minnesotta QOL questionnaire and NYHA functional class and CCS angina class determinations. RESULTS: There were no deaths or new interventions during the study period. There were no significant variations in SPECT scans, QOL scores and stress tests results during medical treatment in the included patients. After the 3rd post operative month, there was improvement in SPECT segmental scores, SSS (18.38±7.51 vs. 15.31±7.29, P=0.003) and SRS (11.92±7.49 vs. 8.53±6.68, P=0.002). The ischemic area extension, however, had non-significant variation (23.38±13.12 percent vs. 20.08±13.88 percent, P=0.1). Stress tests METs varied from 7.66±4.47 pre to 10.29±4.36 METs post-op (P=0.08). QOL score improved from 48.23±18.35 pre to 30.15±20.13 post-op points (P=0.02). NYHA class was 3.15±0.38 pre vs. 1.77±0.83 post-op (P=0.001) and angina CCS class, 3.08±0.64 vs. 1.77±0.83 (P=0.001). CONCLUSIONS: Intramyocardial VEGF165 therapy for refractory angina, in this small trial of no option patients, resulted feasible and safe. Early clinical and scintilographic data showed improvements in symptoms and myocardial perfusion, with regression of ischemia severity in treated areas.

Marca-passo permanente após implante percutâneo valvular aórtico: a necessidade é maior que imaginávamos? / Permanent pacemaker after percutaneous aortic valve implantation: is the need greater than we had anticipated?

O implante percutâneo valvular aórtico é uma alternativa promissora no tratamento da estenose aórtica grave de pacientes com elevado risco cirúrgico. No entanto, parte desses pacientes pode desenvolver distúrbios do sistema de condução elétrico do coração e necessidade de implante de marca-passo permanente. O mecanismo das alterações do sistema de condução não está completamente elucidado. Nosso objetivo é avaliar a frequênia e os fatores relacionados à necessidade de marca-passo permanente em nosso meio. Método: Série de casos com descrição das variáveis absolutas e relativas associadas à necessidade de marca-passo permanente em pacientes submetidos a implante percutâneo valvular aórtico no Instituto de Cardiologia do Rio Grande do Sul. Resultados: Entre novembro de 2008 e novembro de 2009, 10 pacientes foram submetidos a implante percutâneo valvular...

BACKGROUND: Percutaneous aortic valve implantation (PAVI) is a promising alternative treatment for severe aortic stenosis in high surgical risk patients. However, part of these patients may develop electrical conduction system disturbances and require permanent pacemaker implantation. The mechanism of such electrical conduction system disturbances has not been totally elucidated. Our objective is to assess the frequency and factors related to the need of a permanent pacemaker (PPM) in this scenario. METHOD: A series of cases describing absolute and relative variables associated to PPM implantation in patients submitted to PAVI at Instituto de Cardiologia do Rio Grande do Sul. RESULTS: Between November 2008 and November 2009, ten patients were submitted to PAVI using the CoreValveTM prosthesis. Two patients who died due to complications not associated to the conduction system disturbances were excluded. The procedure was successfully carried out in the eight remaining patients, with gradient reduction between the left ventricle and aorta and symptomatic relief. Most of the patients were women (75%) and mean age was 86 years. PPM was required in six patients (75%) after PAVI. The single procedure related event was the development of left bundle branch block (LBBB). During clinical follow-up, one patient resumed sinus rhythm, two alternated their own rhythm with the pacemaker rhythm and three remain totally dependent of artificial stimulus. CONCLUSIONS: We observed an increased need of PPM after PAVI and the development of LBBB seems to be associated to it. Additional and powered studies, comparing other techniques, are required to define the exact incidence of rhythm disturbances caused by PAVI.