RESUMEN
Se acerca el séptimo aniversario del primer procedimiento de desnervación renal vía catéter en la hipertensión arterial resistente. Al "final del principio" es oportuno reflexionar sobre la próxima fase en el desarrollo y la aplicación clínica de la desnervación renal en el tratamiento de la hipertensión arterial. Los problemas técnicos y de procedimiento no resueltos son cruciales: ¿Cuán óptima es la desnervación renal? ¿La desnervación unilateral, comúnmente utilizada en la actualidad, es beneficiosa? ¿La desnervación renal mostrará un "efecto de clase", con un descenso de la presión arterial equivalente al observado con las distintas formas de energía utilizadas actualmente para la ablación nerviosa renal? El talón de Aquiles en los estudios de desnervación renal vía catéter para la hipertensión arterial grave es el fracaso casi universal en la aplicación de una prueba confirmatoria de la desnervación. Al evaluar la eficacia del procedimiento, utilizando mediciones de difusión del excedente de noradrenalina (spillover) desde los nervios simpáticos renales al plasma, la única prueba validada hasta el momento, se halló desnervación incompleta y no uniforme entre pacientes. Es probable que el grado de desnervación haya sido en general subóptimo en los estudios de desnervación renal. Esta crítica también se aplica especialmente al ensayo Symplicity HTN-3, en el cual los especialistas a cargo de realizar el procedimiento, a pesar de ser cardiólogos intervencionistas expertos, no tenían experiencia previa en la técnica de desnervación renal. Su curva de aprendizaje cayó durante el ensayo, una deficiencia acentuada por el hecho de que un tercio de los cirujanos realizaron solo un procedimiento. Los resultados del Symplicity HTN-3 recientemente presentados confirman que la desnervación renal no se logró efectiva y consistentemente en el ensayo.
The seventh anniversary of the first catheter-based renal denervation procedure for resistant hypertension is near. At the "end of the beginning", it is timely to reflect on the next phase in the development and clinical application of renal denervation in hypertension treatment. Unresolved procedural and technical questions are central: To what extent is renal denervation optimal? Is unilateral denervation, now commonly used, beneficial? Will renal denervation show a "class effect", with the different energy forms now used for renal nerve ablation producing equivalent blood pressure lowering? The Achilles heel in catheter-based studies of renal denervation for severe hypertension is the almost universal failure to apply a confirmatory test for renal denervation. When I assessed renal denervation efficacy, using measurements of the spillover of norepinephrine from the renal sympathetic nerves to plasma, the only test validated to this point, denervation was found to be incomplete and non-uniform between patients. It is probable that the degree of denervation has typically been sub-optimal in renal denervation trials. This criticism applies with special force to the Symplicity HTN-3 trial, where the proceduralists, although expert interventional cardiologists, had no prior experience with the renal denervation technique. Their learning curve fell during the trial, a shortcoming accentuated by the fact that one third of operators performed one procedure only. Recently presented results from the Symplicity HTN-3 trialists confirm that renal denervation was not effectively or consistently achieved in the trial.
RESUMEN
Fundamento: A hipertensão arterial sistêmica constitui importante problema de saúde pública e significativa causa de mortalidade cardiovascular. A elevada prevalência e as reduzidas taxas de controle tensional despertaram o interesse por estratégias terapêuticas alternativas. A denervação simpática renal percutânea surgiu como perspectiva no tratamento de hipertensos resistentes. Objetivo: Avaliar a factibilidade e a segurança da denervação renal com cateter irrigado. Métodos: Dez hipertensos resistentes foram submetidos ao procedimento. O desfecho primário foi a segurança, avaliada por eventos adversos periprocedimento, função renal e anormalidade vascular renal aos 6 meses. Os desfechos secundários constituíram mudanças na pressão arterial (consultório e monitorização ambulatorial) e no número de anti-hipertensivos aos 6 meses. Resultados: A média de idade foi de 47,3 (± 12) anos, 90% eram mulheres. No primeiro caso, houve dissecção de artéria renal causada por trauma da bainha, fato que não se repetiu após ajuste técnico, demonstrando efeito da curva de aprendizado. Nenhum caso de trombose/infarto renal ou óbito foi reportado. Não se observou elevação dos níveis séricos de creatinina durante o seguimento. Aos 6 meses, diagnosticou-se um caso de estenose significativa de artéria renal, sem repercussão clínica. A denervação renal reduziu a pressão arterial de consultório, em média, em 14,6/6,6 mmHg (p = 0,4 tanto para pressão arterial sistólica como para a diastólica). A redução média da pressão arterial pela monitorização ambulatorial foi de 28/17,6 mmHg (p = 0,02 e p = 0,07 para pressão arterial sistólica e diastólica, ...
Background: Systemic hypertension is an important public health problem and a significant cause of cardiovascular mortality. Its high prevalence and the low rates of blood pressure control have resulted in the search for alternative therapeutic strategies. Percutaneous renal sympathetic denervation emerged as a perspective in the treatment of patients with resistant hypertension. Objective: To evaluate the feasibility and safety of renal denervation using an irrigated catheter. Methods: Ten patients with resistant hypertension underwent the procedure. The primary endpoint was safety, as assessed by periprocedural adverse events, renal function and renal vascular abnormalities at 6 months. The secondary endpoints were changes in blood pressure levels (office and ambulatory monitoring) and in the number of antihypertensive drugs at 6 months. Results: The mean age was 47.3 (± 12) years, and 90% of patients were women. In the first case, renal artery dissection occurred as a result of trauma due to the long sheath; no further cases were observed after technical adjustments, thus showing an effect of the learning curve. No cases of thrombosis/renal infarction or death were reported. Elevation of serum creatinine levels was not observed during follow-up. At 6 months, one case of significant renal artery stenosis with no clinical consequences was diagnosed. Renal denervation reduced office blood pressure levels by 14.6/6.6 mmHg, on average (p = 0.4 both for systolic and diastolic blood pressure). Blood pressure levels on ambulatory monitoring decreased by 28/17.6 mmHg (p = 0.02 and p = 0.07 for systolic and diastolic blood pressure, respectively). A mean reduction of 2.1 antihypertensive drugs was observed. Conclusion: Renal denervation is feasible and safe in the treatment of resistant systemic arterial hypertension. Larger studies are required to confirm our findings. .