Exercise-induced changes in E/E' ratio in patients with suspected coronary artery disease

Additional roles of diastolic parameters in the diagnosis of obstructive coronary artery disease

BACKGROUND

A recent guideline emphasizes the role of four indicators, including annular e´ velocity, E/e´, left atrial (LA) size, and peak tricuspid regurgitation (TR) velocity, in the assessment of left ventricular (LV) diastolic dysfunction. This study was performed to determine the relationships among these four parameters and obstructive coronary artery disease (CAD).

METHODS

The study data were obtained from a nation-wide registry, composed of 1307 patients (age, 60.4 ± 10.8 years; 964 women) with normal LV ejection fraction (LVEF) who underwent invasive coronary angiography in the suspicion of CAD. Septal e´, E/e´, LA dimension (LAd), and TR velocity were assessed by transthoracic echocardiography.

RESULTS

Compared with patients without obstructive CAD, those with obstructive CAD showed changes in diastolic parameters indicating more progressed LV diastolic dysfunction in univariate analyses. In multiple logistic regression analysis, low septal e´ velocity (<7 cm/s) was identified as an independent risk factor associated with obstructive CAD (odd ratio, 1.91; 95% confidence interval, 1.08-3.36; P = 0.026). Receiver-operating characteristic curve analysis showed that septal e´ velocity had the most powerful value in the detection of obstructive CAD than the other three diastolic parameters (P < 0.01 for each comparison). Septal e´ velocity significantly increased diagnostic value of treadmill exercise test (TET) in the detection of obstructive CAD (P < 0.001 for integrated discrimination improvement index).

CONCLUSIONS

Among the four diastolic parameters, septal e´ velocity had the most powerful relationship with obstructive CAD in stable patients with normal LVEF. The addition of septal e´ velocity could improve the diagnostic value of TET.

The impact of aircraft noise on vascular and cardiac function in relation to noise event number: a randomized trial

Aims

Nighttime aircraft noise exposure has been associated with increased risk of hypertension and myocardial infarction, mechanistically linked to sleep disturbance, stress, and endothelial dysfunction. It is unclear, whether the most widely used metric to determine noise exposure, equivalent continuous sound level (L_eq), is an adequate indicator of the cardiovascular impact induced by different noise patterns.

Methods and results

In a randomized crossover study, we exposed 70 individuals with established cardiovascular disease or increased cardiovascular risk to two aircraft noise scenarios and one control scenario. Polygraphic recordings, echocardiography, and flow-mediated dilation (FMD) were determined for three study nights. The noise patterns consisted of 60 (Noise60) and 120 (Noise120) noise events, respectively, but with comparable L_eq, corresponding to a mean value of 45 dB. Mean value of noise during control nights was 37 dB. During the control night, FMD was 10.02 ± 3.75%, compared to 7.27 ± 3.21% for Noise60 nights and 7.21 ± 3.58% for Noise120 nights (P < 0.001). Sleep quality was impaired after noise exposure in both noise scenario nights (P < 0.001). Serial echocardiographic assessment demonstrated an increase in the E/E′ ratio, a measure of diastolic function, within the three exposure nights, with a ratio of 6.83 ± 2.26 for the control night, 7.21 ± 2.33 for Noise60 and 7.83 ± 3.07 for Noise120 (P = 0.043).

Conclusions

Nighttime exposure to aircraft noise with similar L_eq, but different number of noise events, results in a comparable worsening of vascular function. Adverse effects of nighttime aircraft noise exposure on cardiac function (diastolic dysfunction) seemed stronger the higher number of noise events.

A systematic review of diastolic stress tests in heart failure with preserved ejection fraction, with proposals from the EU-FP7 MEDIA study group

AIMS

Cardiac function should be assessed during stress in patients with suspected heart failure with preserved ejection fraction (HFPEF), but it is unclear how to define impaired diastolic reserve.

METHODS AND RESULTS

We conducted a systematic review to identify which pathophysiological changes serve as appropriate targets for diagnostic imaging. We identified 38 studies of 1111 patients with HFPEF (mean age 65 years), 744 control patients without HFPEF, and 458 healthy subjects. Qualifying EF was >45-55%; diastolic dysfunction at rest was a required criterion in 45% of studies. The initial workload during bicycle exercise (25 studies) varied from 12.5 to 30 W (mean 23.1 ± 4.6), with increments of 10-25 W (mean 19.9 ± 6) and stage duration 1-5 min (mean 2.5 ± 1); targets were submaximal (n = 8) or maximal (n = 17). Other protocols used treadmill exercise, handgrip, dobutamine, lower body negative pressure, nitroprusside, fluid challenge, leg raising, or atrial pacing. Reproducibility of echocardiographic variables during stress and validation against independent reference criteria were assessed in few studies. Change in E/e' was the most frequent measurement, but there is insufficient evidence to establish this or other tests for routine use when evaluating patients with HFPEF.

CONCLUSIONS

To meet the clinical requirements of performing stress testing in elderly subjects, we propose a ramped exercise protocol on a semi-supine bicycle, starting at 15 W, with increments of 5 W/min to a submaximal target (heart rate 100-110 b.p.m., or symptoms). Measurements during submaximal and recovery stages should include changes from baseline in LV long-axis function and indirect echocardiographic indices of LV diastolic pressure.

Tissue Doppler imaging for diagnosis of coronary artery disease: a systematic review and meta-analysis

Global and regional left ventricular (LV) systolic dysfunction is a marker of coronary artery disease (CAD), which is conventionally assessed using two-dimensional echocardiography. Tissue Doppler imaging (TDI) has emerged as an adjunct tool in the diagnosis of regional wall motion abnormalities from CAD. We performed a systematic review and meta-analysis to assess the efficacy of TDI indices in the diagnosis of CAD. We searched MEDLINE and the Cochrane Library for controlled studies comparing TDI measurements in those with and without CAD as confirmed by coronary angiography. Meta-analyses of mean differences in TDI velocities between these populations were performed. Screening of titles and abstracts followed by full-text screening identified 8 studies. At rest, TDI was associated with a significant decrease in the pooled maximum systolic velocity among CAD patients compared to those without CAD [mean difference (MD): -0.66; 95% confidence interval (CI): -0.98 to −0.34]. There were no significant differences in maximum early and late diastolic velocities. Post-stress, TDI was associated with a significant decrease in maximum early diastolic velocity (MD: -1.91; 95% CI: -2.74 to −1.09) and maximum late diastolic velocity (MD: -1.57; 95% CI: -2.95 to −0.18) among CAD patients compared to those without CAD. There was no significant difference in maximum systolic velocity post-stress. Our results suggest that TDI may have a role in the evaluation of CAD. Future studies should evaluate the incremental value of TDI velocities over LV ejection fraction and two dimensional wall motion analysis in the detection of CAD and assessment of its severity. (Word Count: 249)

The diastolic stress test: a new approach to an old problem

The evaluation of ischemic heart disease is the cornerstone of clinical Cardiology. Although there are many means of ischemic evaluation, all are with their own limitations. While perfusion-based studies are highly sensitive, they lack specificity. Conversely, systolic wall motion analysis with echocardiography tends to have high specificity; however, the sensitivity may be limited by short duration of systolic abnormalities when present. With the advent of Doppler echocardiography, and more specifically tissue Doppler imaging, and strain and strain rate imaging, a more comprehensive evaluation of the left ventricular function is available, including diastole. Diastolic abnormalities in the setting of ischemia are now being studied using these new parameters and have been suggested as a reliable marker of ischemia. Exercise-induced abnormalities in diastolic parameters have improved sensitivities and specificities over traditional stress testing and persist longer than systolic abnormalities. A review of the medical literature regarding the subject will be discussed here.