Diastolic stress echocardiography

Exploring the impact of angiotensin-converting enzyme (ACE) gene polymorphism on early diastolic function in hypertension using four-dimensional echocardiography

BACKGROUND

This study explores the relationship between angiotensin-converting enzyme (ACE) gene polymorphisms and early diastolic dysfunction in patients with hypertension utilizing four-dimensional echocardiography and assesses the prognosis.

METHODS

This study consecutively selected 470 patients with hypertension who visited the Fourth Affiliated Hospital of Soochow University between September 2021 and August 2022, with 274 meeting the inclusion criteria. Hypertension gene testing was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques, and the Hardy-Weinberg equilibrium test was used to confirm genetic equilibrium. Patients were categorized into the D allele group (n = 163) and the non-D allele group (n = 111). Diastolic function was assessed using four-dimensional echocardiography, which included averaging the E/e' ratio over three cardiac cycles, measuring the left atrial (LA) maximum volume index (LA volume), tricuspid regurgitation velocity (TR velocity), LA strain, and left ventricular isovolumic relaxation time (IVRT). Patients were subsequently classified into the diastolic dysfunction group (n = 133) and the normal diastolic function group (n = 141). Chi-square tests were used to analyze differences in diastolic function indicators between the groups, Logistic regression was applied to control for potential confounding factors, and receiver operating characteristic (ROC) curves were plotted to assess the predictive value of different ACE alleles for diastolic dysfunction in patients with hypertension.

RESULTS

The genotype distribution in both the D allele group and the non-D allele group was consistent with Hardy-Weinberg equilibrium (P > 0.05). Compared to the non-D allele group, echocardiographic indicators in the D allele group showed a decline in diastolic function: the average E/e' ratio over three cardiac cycles (14.67 [13.82, 15.80] vs. 9.30 [8.12, 12.00]), LA volume (32.76 [29.34, 34.61] vs. 25.61 [22.63, 29.64] ml/m2), TR velocity (2.90 [2.40, 2.90] vs. 1.40 [1.10, 2.40] cm/s), LA strain (18.00 [14.00, 25.00] vs. 37.00 [24.00, 40.00] %), and IVRT (104.25 [95.87, 106.25] vs. 88.09 [80.99, 96.56] ms). Differences between each group were statistically significant (all P < 0.05). The number of patients with diastolic dysfunction was higher in the D allele group (n = 102; 62.6%) compared to the non-D allele group (n = 31; 27.9%). In the logistic regression model, the D allele was associated with an increased risk of early diastolic dysfunction in hypertension (OR = 4.32, 95% CI = 2.56-7.27, P < 0.01). In the adjusted model, the D allele remained associated with an elevated risk of early diastolic dysfunction in hypertension (OR = 3.83, 95% CI = 2.24-6.54, P < 0.01). ROC curve analysis indicated that the D allele has predictive value for early diastolic dysfunction in patients with hypertension (area under the curve [AUC], 0.667; 95% confidence interval [CI], 0.608-0.723; sensitivity, 76.7%; and specificity, 56.7%; P < 0.05).

CONCLUSIONS

The ACE-D allele is associated with early diastolic dysfunction in hypertension. ACE gene testing can enhance the predictive value for diastolic dysfunction in patients with hypertension.

Functional and Metabolic Imaging in Heart Failure with Preserved Ejection Fraction: Promises, Challenges, and Clinical Utility

Heart failure with preserved ejection fraction (HFpEF) is recognised as an increasingly prevalent, morbid and burdensome condition with a poor outlook. Recent advances in both the understanding of HFpEF and the technological ability to image cardiac function and metabolism in humans have simultaneously shone a light on the molecular basis of this complex condition of diastolic dysfunction, and the inflammatory and metabolic changes that are associated with it, typically in the context of a complex patient. This review both makes the case for an integrated assessment of the condition, and highlights that metabolic alteration may be a measurable outcome for novel targeted forms of medical therapy. It furthermore highlights how recent technological advancements and advanced medical imaging techniques have enabled the characterisation of the metabolism and function of HFpEF within patients, at rest and during exercise.

Impaired global longitudinal strain in elderly patients with preserved ejection fraction is associated with raised post-exercise left ventricular filling pressure

BACKGROUND

The purpose of this study was to evaluate whether impaired resting global longitudinal strain (GLS) in elderly patients with preserved left ventricular (LV) ejection fraction (EF) is associated with raised post-exercise LV filling pressure estimated by the ratio of early diastolic transmitral flow velocity to annulus velocity (E/e').

METHODS

Seventy elderly patients (age = 74 ± 6 years, male 40 patients) who underwent treadmill stress echocardiography were studied. All patients had normal sinus rhythm, normal LV wall motion at rest, and had preserved LVEF ≥ 50%. Patients with exercise induced wall motion abnormality were not included. GLS at rest was measured using automated functional imaging.

RESULTS

Twenty-four of the 70 patients had raised post-exercise LV filling pressure indicated by septal E/e' ≥ 15.0. Patients with raised post-exercise LV filling pressure had smaller resting GLS than that in patients without it (- 16.9 ± 1.8 vs. - 19.6 ± 2.5%, respectively, p < 0.0001). Downward stepwise multivariate logistic regression analysis demonstrated that resting GLS was one of independent predictors of raised post-exercise E/e'. Receiver operating characteristic (ROC) curve analysis had demonstrated that optimal cutoff point for resting GLS to predict raised post-exercise E/e' was - 17.8% (sensitivity 83.3%, specificity 80.4%, respectively), and the area under the ROC curve was 0.820.

CONCLUSION

In elderly patients with preserved LVEF and without obvious myocardial ischemia, impaired resting GLS at rest is associated with raised post-exercise LV filling pressure estimated by E/e' ≥ 15.0.

Diastolic stress test echocardiography in patients with suspected heart failure with preserved ejection fraction: a pilot study

AIMS

The purpose of this pilot study was to assess the potential usefulness of diastolic stress test (DST) echocardiography in patients with suspected heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

Patients with suspected HFpEF (left ventricular ejection fraction ≥ 50%, exertional dyspnoea, septal E/e' at rest 9-14, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) at rest < 220 pg/mL; n = 13) and a control group constituted from asymptomatic patients with arterial hypertension (n = 19) and healthy subjects (n = 18) were included. All patients were analysed by two-dimensional and Doppler echocardiography at rest and during exercise (DST) and underwent cardiopulmonary exercise testing and NT-proBNP analysis during exercise. HFpEF during exercise was defined as exertional dyspnoea and peak VO₂  ≤ 20.0 mL/min/kg. In patients with suspected HFpEF at rest, 84.6% of these patients developed HFpEF during exercise, whereas in the group of asymptomatic patients with hypertension and healthy subjects, the rate of developed HFpEF during exercise was 0%. Regarding the diagnostic performance of DST to detect HFpEF during exercise, an E/e' ratio >15 during exercise was the most accurate parameter to detect HFpEF (accuracy 86%), albeit a low sensitivity (45.5%). Nonetheless, combining E/e' with tricuspid regurgitation (TR) velocity > 2.8 m/s during exercise provided a significant increase in the sensitivity to detect patients with HFpEF during exercise (sensitivity 72.7%, specificity 79.5%, and accuracy 78%). Consistent with these findings, an increase of E/e' was significantly linked to worse peak VO₂ , and the combination of an increase of both E/e' and TR velocity was associated with elevated NT-proBNP values during exercise.

CONCLUSIONS

The findings of this pilot study suggest that DST using E/e' ratio and TR velocity could be of potential usefulness to diagnose HFpEF during exercise in patients with suspected HFpEF at rest.