Influence of Angiotensin-Converting Enzyme I/D Gene Polymorphism on the Right Ventricular Myocardial Performance Index in Patients With a First Acute Anterior Myocardial Infarction

Early right ventricular dysfunction after primary percutaneous coronary intervention in anterior versus isolated inferior myocardial infarction assessed by tissue Doppler imaging and speckle tracking echocardiography

This study hypothesized that imaging provides information indicating the right ventricular (RV) involvement after anterior or inferior ST-elevation myocardial infarction (STEMI), beyond standard electrocardiogram (ECG) due to the increasing interest in RV function and assessment techniques. This study aimed to compare RV function between anterior and inferior MI without RV involvement using different echocardiographic modalities. This study included 100 patients with anterior (50 patients) and inferior (50 patients) STEMI, who underwent primary percutaneous coronary intervention (PPCI) and two-dimensional echocardiographic imaging within 24 h after PPCI with RV function analysis by left ventricular (LV) infarct size, LV filling pressure, and RV strain rate. Our primary endpoint was the subclinical RV dysfunction in anterior or inferior MI using tissue Doppler and speckle tracking (STE). The study population included 80 (80%) males and 20 (20%) females. Patients with the anterior STEMI had higher mean creatine kinase-MB (CKMB) and troponin than those with inferior STEMI. This study revealed worse RV dysfunction in patients with anterior than those with inferior STEMI, as reflected by significantly lower RV systolic function, tricuspid annular plane systolic excursion (p ≤ 0.0001), tissue Doppler-derived velocity (p ≤ 0.0001), and STE-derived strain magnitude and rate (p ≤ 0.0001). RV dysfunction occurs in patients without ECG evidence of RV STEMI. RV dysfunction is worse in anterior than inferior MI. Moreover, RV systolic functions were affected by declined LV ejection fraction irrespective of the infarction site, which clinically implies prognostic, treatment, survival rate, and outcome improvement between both conditions. (Trial registration ZU-IRB#:4142/26-12-2017 Registered 26 December 2017, email: IRB_123@medicine.zu.edu.eg).

RIGHT VENTRICLE FUNCTION IN PATIENTS WITH ANTERIOR MYOCARDIAL INFARCTION: ARE WE SURE IT IS NOT INVOLVED?

The right and left ventricle of heart are intimately connected by anatomical and functional links. Hence, acute changes in cardiac geometry and function can modify the performance and physiology of both sides of the heart, influencing each other. After a brief overview of the anatomy and related imaging techniques for the study of right ventricular function, we report a review on the interesting correlation of acute anterior myocardial infarction and right ventricular function, very often underestimated.

Angiotensin-converting enzyme gene insertion/deletion polymorphism with metabolic syndrome in Turkish patients

BACKGROUND

The ACE gene has received substantial attention in recent years as candidate for a variety of diseases. The most common polymorphism in ACE gene is the Insertion/Deletion (I/D, rs4646994) polymorphism located on intron 16.

AIM

We investigated the association between metabolic syndrome (MS) and the insertion (I) - deletion (D) polymorphisms in the angiotensin converting enzyme (ACE) gene in south-east of Turkey.

SUBJECTS AND METHODS

One hundred and sixty subjects, with 101 cases of MS and 59 age- and gender-matched healthy controls were included in the study.

RESULTS

The frequency of ACE I/D polymorphism was found to be 49.5% for DD, 36.6% for ID, and 13.9% for II in the MSstudy group and 44.1% for DD, 42.4% for ID and 13.5% for II in the control group. Allele frequencies were found to be 0.68% for D and 0.32% for I allele in the study group with MS and 0.65% for D, 0.35% for I allele in the control group. The I/D polymorphism of the ACE gene, DD, ID, and II genotypes occurred with similar frequencies in the study group with MS and the control group with no significant differences (p<0.05). On applying one-way analysis of variance to different ACE gene polymorphic groups in patients with MS were not significantly associated to ACE gene polymorphism and waist circumference, systolic blood pressure, diastolic blood pressure, fasting blood glucose, HDL, and LDL (p<0.05).

CONCLUSIONS

Further studies of patients in larger numbers and of different ethnic backgrounds may be necessary to elucidate the association between the ACE I/D gene polymorphism and MS.

Right ventricular involvement in anterior myocardial infarction: a tissue Doppler-derived strain and strain rate study

OBJECTIVE

Strain and strain rate imaging is currently the most popular echocardiographic technique that reveals subclinical myocardial damage. There are currently no available data on this imaging method with regard to assessing right ventricular involvement in anterior myocardial infarction. Therefore, we aimed to evaluate right ventricular regional functions using a derived strain and strain rate imaging tissue Doppler method in patients who were successfully treated for their first anterior myocardial infarction.

METHODS

The patient group was composed of 44 patients who had experienced their first anterior myocardial infarction and had undergone successful percutaneous coronary intervention. Twenty patients were selected for the control group. The right ventricular myocardial samplings were performed in three regions: the basal, mid, and apical segments of the lateral wall. The individual myocardial velocity, strain, and strain rate values of each basal, mid, and apical segment were obtained.

RESULTS

The right ventricular myocardial velocities of the patient group were significantly decreased with respect to all three velocities in the control group. The strain and strain rate values of the right mid and apical ventricular segments in the patient group were significantly lower than those of the control group (excluding the right ventricular basal strain and strain rate). In addition, changes in the right ventricular mean strain and strain rate values were significant.

CONCLUSION

Right ventricular involvement following anterior myocardial infarction can be assessed using tissue Doppler based strain and strain rate.

Structural and functional changes in left and right ventricles after major weight loss following bariatric surgery for morbid obesity

Obesity and bariatric surgery have been associated with changes in ventricular function and structure. The aim of the present study was to assess the long-term changes in left ventricular (LV) and right ventricular (RV) function and structure in patients with morbid obesity-body mass index >or=40 kg/m(2) or >or=35 kg/m(2) with co-morbidities-who had lost weight after bariatric surgery compared to nonsurgical controls. We reviewed 57 patients with morbid obesity who had undergone gastric bypass surgery and who had undergone echocardiography before and after surgery. A reference group (n = 57) was frequency matched for body mass index (+/-2 kg/m(2)), gender, age (+/-2 years), and follow-up duration (+/-6 months). After a mean follow-up of 3.6 years, the LV mass and LV mass indexed by height had decreased in the patients who had undergone bariatric surgery and had lost weight. In contrast, these measurements had increased in the patients who had not undergone bariatric surgery. The difference between these 2 groups remained significant after adjusting for potential confounders. At follow-up, neither the patients nor controls showed a significant change in ejection fraction, LV myocardial performance index, or RV myocardial performance index. In the study population as a whole, multivariate analysis showed a positive correlation between the change in body weight and ventricular septum thickness (R = 0.33), posterior wall thickness (R = 0.31), LV mass (R = 0.38), RV end-diastolic area (R = 0.22), and estimated RV systolic pressure (R = 0.39), all with p values <0.05. In conclusion, body weight changes in patients with morbid obesity were associated with changes in LV structure independent of improvement in obesity-related co-morbidities, including obstructive sleep apnea. Weight loss improved the RV end-diastolic area and might prevent progression to RV dysfunction.

Increased Tei index suggests absence of adequate coronary reperfusion in patients with first anteroseptal acute myocardial infarction

BACKGROUND

The estimation of coronary reperfusion in acute myocardial infarction (AMI) is important. The left ventricular (LV) Tei index is a noninvasive and sensitive parameter expressing overall LV function. We hypothesized that patients without good coronary reperfusion have worse LV function with a higher or worse Tei index compared to those with good reperfusion.

METHODS AND RESULTS

In 85 patients with first anteroseptal AMI, without other cardiac lesions such as prior myocardial infarction, LV hypertrophy or valvular disease, the Tei index was measured using Doppler echocardiography immediately after patients' arrival to the hospital, and the Thrombolysis in Myocardial Infarction (TIMI) grade was evaluated through subsequent coronary angiography. The Tei index was significantly greater in patients who did not have TIMI score of 3 compared to those with a TIMI of 3 (0.60+/-0.13 vs 0.46+/-0.06, p<0.0001). A Tei index >0.50 as the criteria for the absence of TIMI 3 had the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 75, 86, 94, 54 and 78%, respectively.

CONCLUSION

An increased Tei index suggests the absence of adequate coronary reperfusion in patients with first anterior AMI without other lesion.

Association Between A/C1166 Gene Polymorphism of the Angiotensin II Type 1 Receptor and Biventricular Functions in Patients With Acute Myocardial Infarction

BACKGROUND

Although there have been several association studies of angiotensin II type 1 receptor (AT1R, A/C1166) gene polymorphism in clinical endpoints such as myocardial infarction (MI), hypertension, aortic stiffness, and left ventricular mass, the relationship between AT1R polymorphism and biventricular function in acute anterior MI has not been studied before.

METHODS AND RESULTS

The study group comprised 132 consecutive patients who were admitted to the coronary care unit with their first acute anterior MI. Systolic and diastolic diameters, volumes, inflow properties, ejection fraction and myocardial performance index of both ventricles were measured. AT1R polymorphism was determined using polymerase chain reaction amplification. Based on A/C1166 polymorphism of AT1R, the patients were classified into 3 groups: group 1, A/A (n=91) genotype, group 2 A/C (n=28), and group 3 C/C (n=13) genotype. When the left ventricular and right ventricular echocardiographic functions were compared, all parameters of the 3 groups were found to be similar. No difference was detected in either the genotype distribution or allele frequencies between the patients and the controls for AT1R.

CONCLUSIONS

The results suggest that A/C1166 polymorphism of AT1R did not influence the risk of either acute MI or biventricular function after anterior MI.

Prediction of Prognosis in the UM-X7.1 Hamster Model of Congestive Heart Failure Using the Tei Index

BACKGROUND

Cardiac function is difficult to evaluate in small animal models of heart disease. The Doppler Tei index is a simple and non-invasive measure that can express global cardiac function even in small animal models of congestive heart failure. However, its ability to predict prognosis has not been evaluated.

METHODS AND RESULTS

We tested the hypothesis that cardiac functional indices, such as the Tei index, can predict the prognosis of hamsters with cardiac dysfunction. The Tei index, defined as the sum of the isovolume contraction and relaxation time divided by ejection time, and the percent fractional shortening of the left ventricle was measured in 48 anesthetized male hamsters (19.7+/-0.4 weeks old) with cardiac dysfunction (UM-X7.1), using Doppler and 2-dimensional echocardiography. The hamsters were separated into 2 groups based on the median Tei index (0.50) and % fractional shortening (FS) (21%). Kaplan-Meier analysis determined the survival rates of the groups. Both the Tei index and %FS enabled significant distinction of better and poorer survival (p < 0.01), and the survival curves were less overlapped when the animals were separated according to the Tei index.

CONCLUSION

The Tei index can predict prognosis in a small animal model of heart failure.

Assessment of MEF2A Mutations in Myocardial Infarction in Japanese Patients

BACKGROUND

Recently, a mutation in the human MEF2A gene was reported to be responsible for an autosomal dominant form of coronary artery disease, so the purpose of the present study was to assess the significance of MEF2A mutations in Japanese subjects with myocardial infarction (MI).

METHODS AND RESULTS

The study population consisted of 589 control subjects recruited from the Suita study and 379 subjects with MI. The promoter, all the exons, and 3'-UTR regions of MEF2A were sequenced in 190 subjects with myocardial infarction. We found 2 amino acid length polymorphisms, a 7-amino acid deletion polymorphism, and a nonsense mutation (R447X) in exon 12. The length and deletion polymorphisms did not confer susceptibility to MI. Although the nonsense mutation was detected in 1 subject with MI, and in none of the control subjects, the impact of this mutation does not appear to be great; the subject had the MI while in his 70 s, had 2 major risk factors, and no family history of ischemic heart disease.

CONCLUSION

MEF2A polymorphism does not contribute appreciably to MI in the Japanese population.