IL-10 genetic polymorphisms were associated with valvular calcification in Han, Uygur and Kazak populations in Xinjiang, China

OBJECTIVE

Valvular calcification occurs via ongoing endothelial injury associated with inflammation. IL-10 is an anti-inflammatory cytokine and 75% of the variation in IL-10 production is genetically determined. However, the relationship between genetic polymorphisms of IL-10 and valvular calcification has not been studied. The objective of this study was to investigate the association between valvular calcification and IL-10 genetic polymorphisms in the Han, Uygur and Kazak populations in China.

PATIENTS AND METHODS

All of the participants were selected from subjects participating in the Cardiovascular Risk Survey (CRS) study. The single nucleotide polymorphisms (SNPs) rs1800871 and rs1800872 of the IL-10 gene were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Three independent case-control studies involving the Han population, the Uygur population and the Kazak population were used in the analysis.

RESULTS

For the Han and Kazak populations, rs1800871 was found to be associated with valvular calcification in the recessive model, and the difference remained statistically significant following multivariate adjustment (p<0.001, p=0.031, respectively). For the Han, Uygur and Kazak populations, rs1800872 was found to be associated with valvular calcification in the dominant model, and the difference remained statistically significant following multivariate adjustment (p<0.001, p=0.009, and p=0.023,respectively).

CONCLUSION

Both rs1800871 and rs1800872 of the IL-10 gene are associated with valvular calcification in the Han and Kazak populations in China. Rs1800872 is also associated with valvular calcification in the Uygur population.

Percutaneous balloon mitral commissurotomy in indigenous versus non-indigenous Australians

BACKGROUND

Rheumatic heart disease remains a serious health issue amongst the Australian indigenous population. Percutaneous balloon mitral commissurotomy (PBMC) has become the treatment of choice in patients with symptomatic pure mitral stenosis with favourable valve morphology. There is little published data on the efficacy of PBMC in indigenous Australians.

AIMS

We sought to document differences between indigenous Australians (IA) and non-indigenous Australians (NIA) undergoing percutaneous balloon mitral commissurotomy (PBMC) at The Prince Charles Hospital and Holy Spirit Northside Hospital from 1990 to 2006.

METHODS

PBMC was performed in 327 patients using the Inoue-balloon technique (271 female, 56 male, age +/-15 years (mean+/-S.D.), (range 13-89) between March 1990 and March 2006.

RESULTS

The IA population was over represented in this cohort (11% versus an estimated 3.4% of the Queensland population) and comprised the largest non-Caucasian group. Compared with the NIA population they were younger (mean age 36 years (+/-13) versus mean 52(+/-14) years (P<0.05)). Baseline mitral valve area (MVA) was similar in the IA and NIA groups (0.96 cm(2) versus 1.08 cm(2)P=0.9). Mitral valve Echo-score was also similar between the two groups (mean score 7.36 versus 7.52 P=0.8). The IA population had higher pre-procedural mitral valve gradients (14.3 mmHg versus 11.1 mmHg, P<0.05), but less mitral valve calcification. Procedural success was achieved in 91% of both groups. Post procedural MVA (planimetry) was similar (1.98 cm(2) versus 1.84 cm(2)P=0.6), as was percent reduction in mitral valve gradient. Inadequate dilatation was seen in 1 (3%) IA and in 10 (3.6%) of the NIA group. Significant MR was seen in 2 (6%) IA patients and 11 (4%) NIA patients. There were no deaths or strokes or pericardiocenteses in either group.

CONCLUSION

The indigenous population makes up a significant proportion of patients requiring PBMC in Queensland. They present younger and with higher mitral valve gradients. The procedure is safe in both the indigenous and non-indigenous Australian population. Further research is required to establish the long-term efficacy of this procedure in indigenous Australians.

Prevalence of mitral annulus calcification in African Americans: comparison with non-Hispanic whites and Hispanics

BACKGROUND

The association of ethnic ancestry with coronary artery calcifications suggests that mitral annulus calcification may also vary with ethnicity. We sought to compare prevalence and clinical correlates of mitral annulus calcification in non-Hispanic Whites, Hispanics, and African Americans.

DESIGN

This was a retrospective study of 857 patients age 40-75 years that included 217 (25%) African Americans, 349 (41%) Hispanics, and 291 (34%) non-Hispanic Whites referred for echocardiography. Multiple logistic regression was used to determine the interrelationships between mitral annulus calcification, risk factors, and ethnicity.

RESULTS

Mitral annulus calcification was detected in 181 (21.1%) patients including 35 (16.1%) African Americans, 80 (22.9%) Hispanics, and 66 (22.7%) non-Hispanic whites. In univariate analysis, patients with mitral annulus calcification were older and more likely to have hypertension, diabetes, dyslipidemia, smoking history, and two or more risk factors than were those without calcification. In multivariate analysis, age and smoking history were independent predictors of mitral annulus calcification; dyslipidemia and diabetes were borderline significant predictors; and after adjusting for the remaining variables in the model, ethnicity was not an independent significant predictor of mitral annulus calcification.

CONCLUSION

In a retrospective study of middle-aged and elderly African Americans, non-Hispanic Whites, and Hispanics referred for echocardiography, mitral annulus calcification is common in all three major ethnic groups but not significantly associated with ethnic ancestry.

Reproducibility of CT measurements of aortic valve calcification, mitral annulus calcification, and aortic wall calcification in the multi-ethnic study of atherosclerosis

RATIONALE AND OBJECTIVES

Extracoronary calcifications may have clinical significance. The error in extracoronary calcification measurements is still unknown. Accurate quantification of calcifications of the aortic valve (AVC), mitral annulus (MAC), and aortic wall (AWC) may be possible by using cardiac computed tomography (CT). We sought to establish the interscan, interobserver, and intraobserver reproducibility of these measures in all cardiac CT scans in the Multi-Ethnic Study of Atherosclerosis.

MATERIALS AND METHODS

We measured extracoronary calcifications in 100 randomly selected participants to assess interobserver, interscan, and intraobserver variability. Two scans were available for analysis in 99 of these participants, and we quantified thoracic aorta and valvular calcifications.

RESULTS

Mean interscan variability of AVC was 9.7% +/- 11.4% and 8% +/- 10.3% for Agatston and volume scores, with variability of the median at 6.4% and 5.5%, respectively (P > .05). MAC inter-reader variability was 8.2% and 8.9%, with interscan variability of 28% and 33% and intrareader variability of 4% and 4.1%, respectively. For AWC, inter-reader variability was 3%-7.1%, interscan variability was 17%-18%, and intrareader variability was 0.4%-1.4%.

CONCLUSION

AVC, MAC, and AWC measurements are sufficiently reproducible to allow serial investigations over a time suitable for clinical studies.

[Dyspnoea in pregnant female immigrants due to unexpected mitral valve stenosis]

Three female patients, a 22-year-old Moroccan woman, a 25-year-old Turkish woman and a 35-year-old Iraqi woman, became increasingly dyspnoeic during their pregnancy; this was a symptom of congestive heart failure due to mitral valve stenosis. Since all patients were refractory to medical treatment, they underwent invasive therapy by percutaneous transvenous mitral balloon valvotomy (PTMV). In two patients this therapy was successful, but in one patient a closed mitral valvotomy was needed. All three women delivered healthy infants, two immediately following the PTMV; at follow-up 2-4 years later, the women and infants were all doing well. The prevalence of mitral valve stenosis in the western world is increasing because of changing immigration patterns. When pregnant patients start complaining about dyspnoea, especially if they are immigrants, one should be aware of the possibility of mitral valve stenosis. PTMV is a safe and successful treatment for these patients and is preferred above surgical therapy because of its low morbidity and mortality for both mother and foetus. PTMV must be performed in a thoracic surgery centre by an experienced team and the X-ray exposure should be minimised.

Association between transforming growth factor-beta1 gene C-509T and T869C polymorphisms and rheumatic heart disease

BACKGROUND

Scarring and collagen deposition in the valves and destruction of myocytes may result from the combined effects of a smoldering rheumatic process and a constant trauma to the mitral valve or aortic valve by the turbulent flow in rheumatic heart disease (RHD). Transforming growth factor-beta1 (TGF-beta1) may be responsible for the increased valvular fibrosis and calcification in the pathogenesis of RHD. However, the role of TGF-beta1 genetic variant in RHD has not been studied. This case-controlled study was carried out to investigate the possible relationship between the TGF-beta1 gene C-509T and T869C polymorphisms and RHD among the Chinese population in Taiwan.

METHODS

A group of 115 patients with RHD documented by using echocardiography and 100 age- and sex-matched healthy control patients were studied. TGF-beta1 gene C-509T and T869C polymorphisms were identified with polymerase chain reaction-based restriction analysis.

RESULTS

A significant difference was seen in the distribution of genotypes between patients with RHD and control patients for either TGF-beta1 C-509T polymorphism (P <.0001) or T869C polymorphism (P <.0001). The frequency of TGF-beta1 C-509T CC genotype was lower in the RHD group than in the control group (chi2 = 19.05, P <.0001), which suggests that this genotype may confer protective effects against RHD. A significant difference was seen in the distribution of allelic frequency between patients with RHD and control patients for TGF-beta1 T869C polymorphism (P =.04). The odds ratio (OR) for risk of RHD associated with TGF-beta1 T869C T allele was 1.49 (95% CI, 1.02-2.19). Further categorization of patients with RHD into mitral valve disease and combined valve disease subgroups revealed no statistical difference in these gene polymorphisms when compared with the 2 subgroups.

CONCLUSIONS

Patients with RHD have a lower frequency of TGF-beta1 C-509T CC genotype and a higher frequency of T869C T allele, which supports a role for the TGF-beta1 gene C-509T and T869C polymorphisms in determining the risk/protection of RHD in Taiwan Chinese patients.

Natural history of moderate mitral valve stenosis

BACKGROUND

With the introduction of surgery and percutaneous balloon valvuloplasty for relieving severe mitral stenosis the natural history of the disease has markedly altered.

OBJECTIVES

To determine the natural history of the disease in patients with moderate mitral valve stenosis.

METHODS

Demographic, clinical and echocardiographic data were evaluated in 36 patients with moderate mitral stenosis during a follow-up of 71 +/- 15 months.

RESULTS

The 36 patients comprised 32 women and 4 men with a mean age of 43.7 +/- 12.2 years; 28 were Jewish and 8 were of Arab origin. During follow-up, there was a significant decrease in mitral valve area, with an increase in mean mitral valve gradient and score. Mean loss of mitral valve area was 0.04 +/- 0.11 cm 2/year. No correlation was found between disease progression and age, past mitral valve commissurotomy, baseline mean gradient or mitral valve score. Larger baseline mitral valve area (P = 0.007) and Arab origin (P = 0.03) had an independent correlation to loss of mitral valve area. Fifteen patients (42%) did not demonstrate any loss in mitral valve area during the follow-up period.

CONCLUSIONS

The rate of mitral valve narrowing in patients with moderate mitral stenosis is variable and cannot be predicted by patient's age, past commissurotomy, valve score or gradient. Secondly, larger baseline mitral valve area and Arab origin showed an independent correlation to loss of mitral valve area; and finally, in many patients valve area did not change over a long observation period.