Prognostic value of Doppler echocardiographic-derived coronary flow velocity reserve of left anterior descending artery in octogenarians with stress echocardiography negative for wall motion criteria

Clinical Profile and Outcome in Patients with Coronary Slow Flow Phenomenon

The coronary slow flow phenomenon (CSFP) is a poorly recognized clinical entity characterized by delayed distal vessel opacification in the absence of epicardial coronary stenosis and presently lack of specific data on the clinical profile and outcome. We investigated a cohort of 429 patients who fulfilled the criteria for CSFP to explore the clinical feature, outcome, and risk factor of prognosis. Two teams (clinical center and core lab) were blind to patient data for the assessment of coronary angiograph using corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC). The study cohort consisted of 429 patients (294 men, 68.5%), aged from 30 to 78 years (mean, 54 years). Two hundred patients (46.6%) out of 429 patients had a history of hypertension, 72 (16.8%) had diabetes mellitus, and 222 (51.7%) had dyslipidemia. All the rates of agreement between two teams in evaluating whether normal flow (CTFC ≤ 27 frames) or slow flow (CTFC > 27 frames) were moderate (0.40 < κ < 0.75) for the three arteries. Follow-up (mean, 3.8 years) was done for 421 patients (98.1%). The major adverse cardiovascular events (MACE) occurred in 39 patients (9.3%) out of 421 patients. Multivariate analysis showed that the risk of MACE approximately doubles with age >50 years (hazard ratio (HR) = 2.2, 95% CI: 1.0 to 4.9, and P=0.042), hypertension (HR = 2.1, 95% CI: 1.1 to 4.2, and P=0.021), and dyslipidemia (HR = 2.0, 95% CI: 1.0 to 3.9, and P=0.042). CSFP affects predominantly patients at middle age and above but can occur in any age group; CSFP should be more concerned, particularly in patients >50 years old with hypertension and dyslipidemia.

The additive prognostic value of coronary flow velocity reserve during exercise echocardiography

Aims

The aim of the study was to assess the additive prognostic value of coronary flow velocity reserve (CFVR) alongside wall motion analysis during exercise echocardiography in patients with known or suspected coronary artery disease (CAD).

Methods and results

In a prospective, single-centre, observational study, we evaluated 689 patients (449 males; 56 + 9 years) who underwent supine bicycle stress echo (ESE) with CFVR evaluation of the left anterior descending artery (LAD) by Doppler. ESE was positive for regional wall motion abnormalities in 359 (52%) patients. Mean CFVR was 1.9 ± 0.8. During a median follow-up of 36.6 months, there were 200 patients with major adverse cardiac events (MACE): 15 deaths, 17 non-fatal myocardial infarctions [11 of them also had percutaneous coronary intervention with stenting (PCI) or/and coronary artery bypass graft surgery (CABG)] and 179 patients underwent revascularization. The 37 months' event-free survival showed the best outcome for those patients with negative ESE by wall motion criteria and normal CFVR, and the worst outcome for patients with positive ESE by wall motion and abnormal CVFR (99 vs. 42%, P < 0.0001). At multivariable analysis, CFVR in LAD (OR 0.53, 95% CI 0.35-0.79, P < 0.0001), positivity for regional wall motion abnormalities during testing (OR 0.10, 95% CI 0.04-0.25, P < 0.000), previous PCI (OR 0.38, 95% CI 0.16-0.90, P < 0.003), male sex (OR 0.44, 95% CI 0.27-0.71, P < 0.0009), and heart rate reached during exercise (OR 0.98, 95% CI 0.96-0.99, P < 0.02) were independent prognostic predictors of MACE.

Conclusion

In patients with known or suspected CAD, exercise stress tests measuring wall motion criteria and CFVR are additive and complementary for the identification of patients at risk of experiencing major adverse events.

Current themes in myocardial and coronary vascular aging

Advancing age will affect every individual and its impact on cardiac health deserves significant attention. The age-related physiological changes occurring in the coronary vasculature, myocardium, and valves set the stage upon which cardiovascular disease can escalate in the elderly population. The overall focus of this review is to highlight new and noteworthy studies and to incorporate reviews related to cardiac senescence in the context of the current state of the field. Lastly, future directions in the field of cardiac aging and the development of novel therapeutics to treat pathophysiological conditions typically associated with advancing age will be discussed.

Prognostic Value of Coronary Flow Reserve Obtained on Dobutamine Stress Echocardiography and its Correlation with Target Heart Rate

Background:

Normal coronary flow velocity reserve (CFVR) (≥ 2) obtained in the left anterior descending coronary artery (LAD) from transthoracic echocardiography is associated with a good prognosis, but there is no study correlating CFVR with submaximal target heart rate (HR).

Objective:

To evaluate the prognostic value of CFVR obtained in the LAD of patients with preserved (>50%) left ventricular ejection fraction (LVEF) who completed a dobutamine stress echocardiography (DSE), considering target HR.

Methods:

Prospective study of patients with preserved LVEF and CFVR obtained in the LAD who completed DSE. In Group I (GI = 31), normal CFVR was obtained before achieving target HR, and, in Group II (GII = 28), after that. Group III (G III=24) reached target HR, but CFVR was abnormal. Death, acute coronary insufficiency, coronary intervention, coronary angiography without further intervention, and hospitalization were considered events.

Results:

In 28 ± 4 months, there were 18 (21.6%) events: 6% (2/31) in GI, 18% (5/28) in GII, and 46% (11/24) in GIII. There were 4 (4.8%) deaths, 6 (7.2%) coronary interventions and 8 (9.6%) coronary angiographies without further intervention. In event-free survival by regression analysis, GIII had more events than GI (p < 0.001) and GII (p < 0.045), with no difference between GI and GII (p = 0.160). After adjustment, the only difference was between GIII and GI (p = 0.012).

Conclusion:

In patients with preserved LVEF and who completed their DSE, normal CFVR obtained before achieving target HR was associated with better prognosis.

Fundamento:

A reserva de velocidade de fluxo coronariano (RVFC) adequada (≥ 2) obtida na artéria descendente anterior (ADA) através do ecocardiograma transtorácico associa-se a bom prognóstico, mas não há estudo correlacionando-a com a frequência cardíaca (FC) alvo (submáxima).

Objetivo:

Avaliar o valor prognóstico da RVFC obtida na ADA de pacientes com fração de ejeção do ventrículo esquerdo (FEVE) preservada (>50%) e ecocardiograma sob estresse com dobutamina (EED) concluído, considerando a FC alvo submáxima.

Métodos:

studo prospectivo de pacientes com FEVE preservada e RVFC obtida na ADA durante EED concluído. No Grupo I (GI=31), a RVFC adequada foi obtida antes de se atingir a FC alvo, e no Grupo II (G II=28), após. O Grupo III (G III=24) atingiu a FC alvo, mas a RVFC foi inadequada. Foram considerados eventos: óbito, insuficiência coronariana aguda, intervenção coronariana, coronariografia sem intervenção subsequente e internamento hospitalar.

Resultados:

Em 28 ± 4 meses, ocorreram 18 (21,6%) eventos, sendo 6% (2/31) no GI, 18% (5/28) no GII e 46% (11/24) no GIII. Foram 4 (4,8%) óbitos, 6 (7,2%) intervenções coronarianas e 8 (9,6%) coronariografias sem intervenção subsequente. Na sobrevida livre de eventos pela análise de regressão, GIII apresentou mais eventos do que GI (p < 0,001) ou GII (p < 0,045), não havendo diferença entre GI e GII (p = 0,160). Após o ajustamento, foi mantida a diferença apenas entre GIII e GI (p = 0,012).

Conclusão:

Em pacientes com FEVE preservada e EED concluído, a RVFC adequada obtida antes da FC alvo associou-se ao melhor prognóstico.

Effects of nitroglycerine on coronary flow velocity before and during adenosine provocation

BACKGROUND

Transthoracic echocardiography-assessed coronary flow velocity reserve (CFVR) evaluates coronary microvascular arterial function. Coronary flow velocity measurements at baseline and during hyperemia are used to calculate CFVR. Adenosine infusion induces hyperemia but it is not known if it causes a maximal response. We hypothesized that pre-treatment with nitroglycerine before adenosine provocation enhances hyperemia.

METHODS

Twenty-three healthy study subjects (mean age 27.5 ± 5.5, 35% women) underwent CFVR measurements before and after pretreatment with sublingual nitroglycerine (0.5 mg). Hyperemia was induced by adenosine infusion (140 μg/kg/min). In addition, the effect of nitroglycerin on left main coronary artery diameter was assessed.

RESULTS

Pretreatment with nitroglycerine increased median CFVR from 3.6 (range 2.8-4.3) to 5.0 (4.1-6.0), p = 0.002. The increase was caused by a marked reduction in baseline coronary flow velocity 17 (15-24) vs 27 (19-31) cm/s, p < 0.0001) while hyperemic velocity remained unchanged (90 (68-116) vs 93 (75-105) cm/s, p = 0.48). Nitroglycerin significantly dilated the left main coronary artery (from median 3.1 (2.7-3.6) mm to 3.8 (3.1-4.3) mm, p = 0.018).

CONCLUSION

Pretreatment with nitroglycerine dilates coronary arteries and increases coronary flow velocity reserve indicating that adenosine alone causes a submaximal hyperemia.

The declining frequency of inducible myocardial ischemia during stress echocardiography over 27 consecutive years (1983-2009)

BACKGROUND

Previous studies have suggested a decline in positivity of stress cardiac imaging, suggesting the need for developing better strategies for test selection to achieve acceptable cost-effectiveness balance. The aim of this retrospective study was to assess the rate of positivity of stress echocardiography (SE) over 27 consecutive years.

METHODS

We assessed the rate of SE positivity in 2007 patients without previous myocardial infarction or coronary revascularization who performed SE in a tertiary care referral center from 1983 to 2009. SE was performed with dipyridamole (1427), dobutamine (136) or exercise (444).

RESULTS

There was a progressive decline over time in the rate of SE positivity from 42% (1983-1991) to 22% (2001-2009), with a relative increase of patients with low pre-test probability of disease (from 5% to 27%). The percentage of patients studied with SE under anti-ischemic therapy increased markedly (from 8% in the first to 61% in the last nine years).

CONCLUSION

Over 27 consecutive years, we observed a steady decline in SE positivity rate (with >5-fold increase of low probability patients), with almost 8-fold increase in anti-ischemic therapy at testing. We probably need refined criteria of referral for testing and/or better ways to titrate the negative response beyond wall motion abnormalities during SE.

Coronary Flow Velocity Reserve Assessment with Transthoracic Doppler Echocardiography

Coronary flow velocity reserve (CFVR) reflects global coronary atherosclerotic burden, endothelial function and state of the microvasculature. It could be measured using transthoracic Doppler echocardiography in a non-invasive, feasible, reliable and reproducible fashion, following a standardised protocol with different vasodilatory stimuli. CFVR measurement is a recommended complement to vasodilator stress echocardiography. It could serve as a diagnostic tool for coronary microvascular dysfunction and in the setting of epicardial coronary artery stenoses could help in identification and assessment of functional significance of coronary lesions and follow-up of patients after coronary interventions. CFVR has also a prognostic significance in different clinical situations.

Coronary Microvascular Function and Beyond: The Crosstalk between Hormones, Cytokines, and Neurotransmitters

Beyond its hemodynamic function, the heart also acts as a neuroendocrine and immunoregulatory organ. A dynamic communication between the heart and other organs takes place constantly to maintain cardiovascular homeostasis. The current understanding highlights the importance of the endocrine, immune, and nervous factors to fine-tune the crosstalk of the cardiovascular system with the entire body. Once disrupted, this complex interorgan communication may promote the onset and the progression of cardiovascular diseases. Thus, expanding our knowledge on how these factors influence the cardiovascular system can lead to novel therapeutic strategies to improve patient care. In the present paper, we review novel concepts on the role of endocrine, immune, and nervous factors in the modulation of microvascular coronary function.