ABSTRACT
PURPOSE: Persistent microvascular obstruction (MVO) after successful percutaneous coronary intervention (PCI) in acute ST segment elevation myocardial infarction (STEMI) has been well-described. MVO predicts lack of recovery of left ventricular function and increased mortality. Sonothrombolysis utilizing diagnostic ultrasound induced cavitation of commercially available microbubble contrast has been effective at reducing infarct size and improving left ventricular ejection fraction (LVEF) when performed both pre- and post-PCI. However, the effectiveness of post-PCI sonothrombolysis alone after successful PCI has not been demonstrated. METHODS: A prospective randomized controlled trial was performed in 50 consecutive consenting patients with anterior STEMI who underwent a continuous microbubble infusion immediately following successful PCI. Intermittent high mechanical index (MI) impulses were applied only in the sonthrombolysis group. Delayed enhancement magnetic resonance imaging (MRI) was performed at 48 h and again at 6-8 weeks to assess for differences in infarct size, LVEF, and MVO. RESULTS: There were no differences between groups in age, gender, and cardiovascular risk factors. Significant (> 2 segments) MVO following successful PCI was observed in 66% of patients. Although sonothrombolysis reduced the extent of MVO acutely, there were no differences in infarct size, LVEF, or extent of MVO by MRI at 48 h. Twenty-eight patients returned for a follow up MRI at 6-8 weeks. LVEF improved only in the sonothrombolysis group (∆LVEF 7.81 ± 4.57% with sonothrombolysis vs. 1.77 ± 7.02% for low MI only, p = .011). CONCLUSION: Post-PCI sonothrombolysis had minimal effect on reducing myocardial infarct size but improved left ventricular systolic function in patients with acute anterior wall STEMI.
Subject(s)
Percutaneous Coronary Intervention , Humans , Female , Male , Percutaneous Coronary Intervention/methods , Middle Aged , Prospective Studies , Treatment Outcome , ST Elevation Myocardial Infarction/physiopathology , ST Elevation Myocardial Infarction/surgery , Recovery of Function , Myocardial Infarction/physiopathology , Microbubbles , Echocardiography/methods , Microcirculation/physiology , Contrast Media , AgedABSTRACT
BACKGROUND: We aimed to identify, among Chronic Chagas Cardiomyopathy (CCC) patients with left ventricular dysfunction (LVD) and non-left bundle branch block (non-LBBB), subgroups with different functional and mechanical patterns of global longitudinal strain (GLS) and intraventricular dyssynchrony (IVD) at rest and after exercise stress test, and reclassify them using a new echocardiographic approach. METHODOLOGY: In this single-center cross-sectional study, 40 patients with CCC, left ventricular ejection fraction (LVEF) ≤ 35% and non-LBBB underwent rest echocardiography and then treadmill exercise stress echocardiography with GLS and IVD analysis. The sample was divided into four groups, based on GLS and IVD significant variation between rest and exercise: GLS + IVD+ (9 patients); GLS + IVD- (9 patients); GLS-IVD+ (10 patients); GLS-IVD- (10 patients). RESULTS: At rest, median LVEF was 28% (21.3%-33%) and GLS (-7% (-5%/-9.3%), were not different among groups. The average response of GLS was an increase of 0.74% over rest values, and the average response of IVD was a decrease of 6.9 ms. Group GLS-IVD+ presented more dyssynchrony at rest (p = 0.01). Left atrial (LA) volume (higher in GLS-IVD-) (p = 0.022) and TAPSE (higher in GLS + IVD+) (p = 0.015) were also different among groups at baseline. Of the 40 patients evaluated, 27 (67.5%) had very severe LVD (GLS < -8%). In addition, among these patients, 11 patients had contractile reserve after undergoing stress echocardiography. CONCLUSIONS: In patients with CCC, severe LVD and non-LBBB, the evaluation of GLS and IVD between rest and exercise was able to reclassify myocardial function and to identify subgroups with contractile reserve and significant dyssynchronopathy.
Subject(s)
Chagas Cardiomyopathy , Ventricular Dysfunction, Left , Chagas Cardiomyopathy/diagnostic imaging , Cross-Sectional Studies , Echocardiography , Humans , Stroke Volume , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/epidemiology , Ventricular Function, LeftABSTRACT
Fundamento: Microbolhas intravenosas (MB) e ultrassom (US) têm sido utilizados para recanalizar vasos epicárdicos em modelos animais de infarto agudo do miocárdio com supradesnivelamento do segmento ST (IAM-SST). Nenhum estudo prévio demonstrando o valor dessa técnica foi realizado em humanos. Objetivo: Estudo piloto realizado com o objetivo de avaliar a eficácia da utilização de MB e US (sonotrombólise) sobre as taxas iniciais de recanalização de artérias coronarianas em pacientes com IAM-SST. Método: Estudamos 24 pacientes (18 homens, média etária de 58 ± 9 anos) que deram entrada no serviço de emergência com IAM-SST. Pacientes foram randomizados em um dos três grupos: MB + US especificamente desenvolvido para este protocolo, com duração de pulso 4-20 useg e índice mecânico (IM) >1.0 (n = 7), MB + US com impulsos repetitivos de alto IM (1.0), com duração de pulso < 2 useg (n = 8), ou grupo controle (n = 9) que recebeu MB + US apenas paraanalisar a perfusão dentro da área de risco. As MB utilizadas no estudo consistiam em solução de Definity 3%. Todos os pacientes foram submetidos a intervenção coronariana percutânea (ICP). Resultados: As médias dos tempos porta-balão foram 76 ± 35 minutos no grupo MB + US 4-20 useg, 70 ± 20 minutos no grupo MB + US impulsos repetitivos e 81 ± 13 minutos no grupo controle (p = NS). Recanalização angiográfica antes da angioplastia foi observada em 75% dos pacientes tratados com MB + US impulsos repetitivos, em 43% nogrupo tratado com MB + US 4-20 useg e em 11% do grupo controle (p = < 0,05). Conclusão: Utilização de MB e US com impulsos repetitivos pode ser um método para recanalização precoce de artérias epicárdicas em pacientes com IAM-SST.
Background: Intravenous microbubbles (MB) and transthoracic ultrasound (US) have been utilized to recanalize epicardial vessels in animalmodels of ST segment elevation myocardial infarction (STEMI). The feasibility of such an ultrasound-guided approach in humans with STEMIhave not been studied. Objective: Pilot study with the aim to evaluate the efficacy of MB plus US on coronary artery recanalization rate in patients with STEMI. Methods: Twenty-four patients (18 men, mean age 58 ± 9 years) admitted to the emergency room with STEMI were randomized into 3 groups. Patients either received MB plus custom designed high mechanical index (MI) impulses at 4-20 usec pulse duration (n = 7), MB plus diagnostichigh MI (MI = 1.0) with multiple impulses < 2 usec pulse duration (n = 8) or MB plus limited diagnostic high MI impulses (< 5) just to analyzemyocardial perfusion, control group (n = 9). MB utilized in the study consisted of a solution of Definity 3%. All randomized groups underwent emergent PCI.Results: The mean door-to-balloon time were 76 ± 35 minutes in group US 4-20 usec, 70 ± 20 minutes in group US multiple impulses and 81 ± 13 minutes in control group (p = NS). Angiographic recanalization before PCI was observed in 75% of patients treated with US multiple impulses, in 43% for US 4-20 usec and 11% in control (p = <0.05).Conclusion: Utilization of MB and diagnostic US with multiple impulses may be a method of achieving early recanalization in acute STEMI.
