Relationship between myocardial performance index and severity of coronary artery disease assessed with SYNTAX score in stable coronary artery disease

Can Tei Index Predict High Syntax Score in Patients with Chronic Coronary Syndrome and Normal Left Ventricular Systolic Function?

OBJECTIVE

Some patients who had chronic coronary syndrome (CCS) and were recognized as low risk, however, developed cardiovascular events, whereas others who were categorized as high risk did not develop any cardiovascular events. Invasive coronary angiography is the gold standard tool for the assessment of coronary artery disease (CAD) severity. The SYNTAX score (SS) was recently recognized as an invasive angiographic-guided scoring system used in risk stratification of patients who have more than one-vessel CAD and undergoing revascularization with percutaneous cardiovascular intervention. It has a good predictive value of adverse cardiovascular events. Exploration for unique noninvasive modalities that may help in a better way for risk stratification of CCS patients by predicting the severity of CAD (as reflected by SS) would be of a paramount value. Tei index is a promising modality for that objective, which is a Doppler-derived time interval index that combines both systolic and diastolic cardiac performance.

METHODS

We examined the relationship between the severity of CAD as assessed by the SS and Tei index in 100 patients with CCS and normal left ventricular systolic function.

RESULTS

All the studied 100 patients had a normal ejection fraction with mean = 58.92 ± 7.88; the mean value of Tei index was 0.84 ± 0.26. There was a statistically significant positive association between Tei index and SS (P = 0.0001); moreover, there was a correlation between left anterior descending (LAD) affection and Tei index (P = 0.0001).The cutoff point of Tei index to detect SS above 22 was >0.93 (with specificity of 86.5% and sensitivity of 42.4%).

CONCLUSION

Tei index significantly correlates with SS and LAD affection. Moreover, it is a cheap, radiation-free, noninvasive technique and may be used as a further risk stratification modality beyond others.

Risk Stratification for Percutaneous Coronary Intervention

The Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score is a semiquantitative angiographic score developed to prospectively characterize the disease complexity of the coronary vasculature. With more than 50 validation studies, the SYNTAX score is the most-studied risk model in the setting of percutaneous coronary intervention. In this article, the evolutionary journey of the SYNTAX score is reviewed, with emphasis on its sequential modifications and adaptations, now culminating in the development and validation of the SYNTAX score II.

Lower serum 25-hydroxyvitamin D level is associated with impaired myocardial performance and left ventricle hypertrophy in newly diagnosed hypertensive patients

Objective:

Vitamin D deficiency is an independent risk factor for cardiovascular mortality. The relationship between vitamin D level and left ventricle (LV) myocardial performance index (MPI=Tei index), which incorporates both LV systolic function and diastolic function, was not investigated in previous studies. We hypothesized that vitamin D level may be associated with LV function and geometry. We aimed to investigate the association between serum 25-hydroxyvitamin D (25 [OH] D) levels and MPI and LV hypertrophy in hypertensive patients with newly diagnosed and preserved ejection fraction.

Methods:

We studied 151 sequential newly diagnosed hypertensive subjects who lived in the Çukurova region without known cardiovascular risk factors or overt heart disease (mean age: 62.8±10.4 years). Serum 25 (OH) D was measured using a direct competitive chemiluminescent immunoassay. The patients were divided into two groups according to serum 25 (OH) D level: vitamin D-non-deficient group (vitamin D> 20.00 ng/mL, n=53) and vitamin D-deficient group (vitamin D< 20.00 ng/mL, n=98). MPI was defined as the sum of isovolumic contraction and relaxation times divided by the ejection time. LV mass index (LVMI) was calculated by using the Devereux formula and body surface area.

Results:

MPI and LVMI values were lower and low-density lipoprotein (LDL) levels were higher in patients who were vitamin D-non-deficient than patients who were vitamin D-deficient (p<0.05 for all). Multivariate linear regression analysis showed that serum 25 (OH) D was indepen-dently associated with MPI (β=-0.426, p<0.001), LVMI (β=-0.345, p=<0.001), and LDL (β=0.140, p<0.026).

Conclusion:

Lower serum 25 (OH) D levels are significantly associated with impaired myocardial performance and LVMI.

The prognostic value of mechanical left ventricular dyssynchrony in patients with acute coronary syndrome

Background

Echocardiography is a well-established tool for risk stratification in patients with acute coronary syndrome (ACS). ACS has significant impact on LV dyssynchrony, and detrimental effects on systolic function and long term outcome. The aims of this study were to determine whether LV dyssynchrony carries any predictive information in an unselected ACS population and to evaluate if it has any incremental value to the information given from conventional echocardiographic measurements.

Methods

The study included 227 consecutive ACS patients. Primary endpoint was the composite of death, new MI, or rehospitalisation due to heart failure. Dyssynchrony was measured as intersegmental variation of time to peak strain, the post systolic index (PSI) and myocardial performance index (MPI) with the standard deviation and difference between lowest and highest value (delta) expressing the amount of dyssynchrony. Septal-lateral delay was also tested. All dyssynchrony parameters were compared with Ejection fraction (EF).

Results

The median follow up time was 53 months. 85 patients reached the combined endpoint. Patients with and without a subsequent combined endpoint differed significantly regarding calculated SD: s and delta-value for PSI, time to peak 2D-strain and MPI but not regarding septal-lateral delay. In ROC-analysis none of the dyssynchrony parameters had larger AUC than EF. When adjusting for traditional risk factors none of the dyssynchrony parameters remained associated with outcome, whereas EF still did.

Conclusion

LV dyssynchrony seem to have significant prognostic information in patient with acute coronary syndrome but in comparison to conventional parameters such as EF there is no incremental value of this information.