Prognostic value of dobutamine stress myocardial perfusion echocardiography in patients with known or suspected coronary artery disease and normal left ventricular function

A Sonotrombólise Promove Melhora dos Índices de Motilidade e Perfusão do Ventrículo Esquerdo após o Infarto Agudo do Miocárdio

Fundamento

Demonstrou-se recentemente que a aplicação de ultrassom de alta energia com microbolhas, técnica conhecida como sonotrombólise, causa a dissolução de trombos intravasculares e aumenta a taxa de recanalização angiográfica no infarto agudo do miocárdio com supradesnivelamento do segmento ST (IAM-CSST).

Objetivo

Avaliar o efeito da sonotrombólise nos índices de motilidade e perfusão miocárdicas em pacientes com IAM-CSST, utilizando a ecocardiografia com perfusão miocárdica em tempo real (EPMTR).

Método

Uma centena de pacientes com IAM-CSST foram randomizados em dois grupos: Terapia (50 pacientes tratados com sonotrombólise e angioplastia coronária primária) e Controle (50 pacientes tratados com angioplastia coronária primária). Os pacientes realizaram EPMTR para analisar a fração de ejeção do ventrículo esquerdo (FEVE), o índice de escore de motilidade segmentar (IEMS) e o número de segmentos com defeito de perfusão miocárdica, 72 horas após o IAM-CSST e com 6 meses de acompanhamento. Foi considerado significativo p < 0,05.

Resultados

Pacientes tratados com sonotrombólise apresentaram FEVE mais alta que o grupo Controle em 72 horas (50 ± 10% vs. 44 ± 10%; p = 0,006), e essa melhora foi mantida em seis meses (53 ± 10% vs. 48 ± 12%; p = 0,008). O IEMS foi similar nos grupos Terapia e Controle em 72 horas (1,62 ± 0,39 vs. 1,75 ± 0,40; p = 0,09), mas tornou-se menor no grupo Terapia em 6 meses (1,46 ± 0,36 vs. 1,64 ± 0,44; p = 0,02). O número de segmentos com defeito de perfusão não foi diferente entre os grupos em 72 horas (5,92 ± 3,47 vs. 6,94 ± 3,39; p = 0,15), mas ficou menor no grupo Terapia em 6 meses (4,64 ± 3,31 vs. 6,57 ± 4,29; p = 0,01).

Conclusão

A sonotrombólise em pacientes com IAM-CSST resulta na melhora dos índices de motilidade e perfusão ventricular ao longo do tempo.

Longitudinal myocardial function is more compromised in cardiac syndrome X compared to insignificant CAD: Role of stress echocardiography and calcium scoring

BACKGROUND AND AIM

The aim of this study was to assess the nature of myocardial dysfunction in the cardiac syndrome X (CSX) and insignificant coronary artery disease (ICAD) using dobutamine stress echocardiography (DSE) and coronary calcium scoring (CAC).

METHODS

We prospectively studied 35 consecutive patients who complained of exertional angina, had ≥1 mm ST shift on exercise stress test but normal or no obstructive CAD (<50%) on angiography. Patients were divided into CSX (n = 27) with normal arteries and ICAD (n = 8) with insignificant stenosis.

RESULTS

CSX patients had more females, lower calcium score and less prevalent cardiac risk factors compared to ICAD (p < 0.05 for all). At peak stress, MAPSE and TAPSE failed to increase in both groups. LV septal and lateral s' increased in the two groups but the increment increase was less in CSX than ICAD (p < 0.05) while other diastolic indices did not differ between groups (p > 0.05 for all). CAC correlated modestly with LV and RV systolic velocities: septal s' (r = -0.65, p < 0.001) lateral s' (r = -0.35, p = 0.04) and right s' (r = -0.53, p = 0.005) in CSX, while in ICAD patients only with RV s' (r = -0.58, p = 0.02). On multivariate model, only septal s' OR 1.816 (1.1090-3.820, p = 0.04) proved the most powerful independent predictor of CAC.

CONCLUSIONS

Compromised LV longitudinal systolic velocities were more pronounced and calcium score as a surrogate for atherosclerosis was lower in CSX than ICAD. These findings strengthen the evidence for different pathogenesis of CSX compared to ICAD, with microvascular disease in the former and calcification in the latter.

Long-term prognostic value of stress myocardial perfusion echocardiography in patients with coronary artery disease: a meta-analysis

AIMS

To evaluate the prognostic value of myocardial perfusion (MP) imaging during contrast stress echocardiography (cSE) in patients with known or suspected coronary artery disease (CAD).

METHODS AND RESULTS

A search in PubMed, Embase databases, and the Cochrane library was conducted through May 2019. The Cochran Q statistic and the I2 statistic were used to assess heterogeneity, and the results were analysed by RevMan V5.3 and Stata V15.1 software. Twelve studies (seven dipyridamole and five exercise/dobutamine) without evidence of patient overlap (same institution publishing results over a similar time period) enrolling 5953 subjects (47% female, 8-80 months of follow-up) were included in the analysis. In all studies, total adverse cardiovascular events were defined as either cardiac death, non-fatal myocardial infarction (NFMI), or need for urgent revascularization. Hazard ratios (HRs) revealed that a MP abnormality [pooled HR 4.75; 95% confidence interval (CI) 2.47-9.14] was a higher independent predictor of total events than abnormal wall motion (WM, pooled HR 2.39; 95% CI 1.58-3.61) and resting left ventricular ejection fraction (LVEF, pooled HR 1.92; 95% CI 1.44-2.55) with significant subgroup differences (P = 0.002 compared with abnormal WM and 0.01 compared with abnormal LVEF). Abnormal MP was associated with higher risks for death [Risk ratio (RR) 5.24; 95% CI 2.91-9.43], NFMI (RR 3.09; 95% CI 1.84-5.21), and need for coronary revascularization (RR 16.44; 95% CI 6.14-43.99).

CONCLUSION

MP analysis during stress echocardiography is an effective prognostic tool in patients with known or suspected CAD and provides incremental value over LVEF and WM in predicting clinical outcomes.

Human microvascular reactivity: a review of vasomodulating stimuli and non-invasive imaging assessment

The microvasculature serves an imperative function in regulating perfusion and nutrient exchange throughout the body, adaptively altering blood flow to preserve hemodynamic and metabolic homeostasis. Its normal functioning is vital to tissue health, whereas its dysfunction is present in many chronic conditions, including diabetes, heart disease, and cognitive decline. As microvascular dysfunction often appears early in disease progression, its detection can offer early diagnostic information. To detect microvascular dysfunction, one uses imaging to probe the microvasculature's ability to react to a stimulus, also known as microvascular reactivity (MVR). An assessment of MVR requires an integrated understanding of vascular physiology, techniques for stimulating reactivity, and available imaging methods to capture the dynamic response. Practical considerations, including compatibility between the selected stimulus and imaging approach, likewise require attention. In this review, we provide a comprehensive foundation necessary for informed imaging of MVR, with a particular focus on the challenging endeavor of assessing microvascular function in deep tissues.

Left ventricular hypertrophy as protective factor after bypass grafting

Left ventricular hypertrophy (LVH) is a well established cardiovascular risk factor, accounting for an increase in cardiovascular morbid-mortality, although how much the magnitude and the kind of LVH could affect cardiovascular outcomes is in large part unknown. We speculate that mild LVH in absence of left ventricular (LV) chamber dilation, could play a protective role towards functional capacity, clinical outcome, cardiovascular and total morbi-mortality in conditions in which LV systolic function is generally reduced. Accordingly to many epidemiological observations, the availability of extra-quote of systolic function could lead to a significative improvement in the final outcome of some kinds of heart patients, as those undergoing bypass-grafting, where the stress for heart and cardiovascular system is always high. We suppose that the functional reserve available for patients with LVH could make the difference with respect to other patients undergoing myocardial revascularization. Similarly, the availability of a contractile reserve warranted by LVH could ensure a little gain in the outcome for patients after other major cardiovascular events (such as myocardial infarction or other heart surgery as surgical valve replacement). However, our hypothesis only involves mild LVH without LV chamber dilation, that is the initial stage of "non-dilated concentric" LVH and "non-dilated eccentric" LVH according to the new four-tiered classification of LVH based on relative wall thickness and LV dilation. Support for our hypothesis derives from the well-known protective role of systolic function that is a major factor in almost all cardiovascular diseases, where LV ejection fraction (LVEF) has shown to significantly improve quality of life, as well as morbidity and mortality. The knowledge that mild LVH in absence of LV chamber dilation is not as harmful in such conditions as believed at present could make avoidable some drugs prescription in some stages of the disease. Furthermore, it may allow a better evaluation of the risk profile of patients with LVH undergoing some cardiovascular major events like bypass grafting, myocardial infarction or surgical heart valve replacement.

Efficacy of noninvasive cardiac imaging tests in diagnosis and management of stable coronary artery disease

The aim of this review was to discuss the current literature regarding the utility of noninvasive imaging in diagnosis and management of stable coronary artery disease (CAD) including recent data from large randomized trials assessing diagnosis and prognosis. Current guidelines recommend revascularization in patients with refractory angina and in those with potential prognostic benefit. Appropriate risk stratification through noninvasive assessment is important in ensuring patients are not exposed to unnecessary invasive coronary angiograms. The past 20 years have seen an unprecedented expansion in noninvasive imaging modalities for the assessment of stable CAD, with cardiovascular magnetic resonance and computed tomography complementing established techniques such as myocardial perfusion imaging, echocardiography and exercise electrocardiogram. In this review, we examine the current state-of-the-art in noninvasive imaging to provide an up-to-date analysis of current investigation and management options.

Non-invasive imaging in cardiology for the generalist

In contrast to invasive techniques, the goal of non-invasive cardiac imaging is to identify or exclude heart disease in response to a patient's clinical history of cardiac localizing symptoms. Imaging also aims to establish the risk of an individual developing future heart disease with a view to preventing major cardiovascular events such as myocardial infarction. As well as a role in risk stratification, non-invasive cardiac imaging also helps with decision making for future medical and procedural interventions. This review outlines the non-invasive imaging modalities available to physicians to identify and risk stratify cardiovascular disease. It discusses the strengths of each imaging technique, in which circumstances it is most useful and its diagnostic accuracy.