IJCS | Volume 32, Nº5, September/October 2019

514 There is little research on hypovitaminosis under this condition in primary care and, especially, when it is correlated with cardiovascular changes. Our study was pioneer in dealing with vitamin D deficiency in primary care. Most studies associate cardiovascular diseases with serum levels of vitamin D. A study indicated that a 25-hydroxyvitamin D (25[OH]D) may be an important marker or modulator of the functional capacity in heart failure patients. 18 Pekkanen et al., 19 investigated whether the (25(OH)D3) concentration would be associated with high cardiovascular risk factors and cardiac structure and function in patients with coronary heart disease. Among other results, they found that low vitamin D is associated with several cardiovascular risk factors and structural cardiac changes, heart failure with preserved ejection fraction and heart failure with reduced ejection fraction. 19 In another study, Polat et al., 20 observed a significant negative correlation between 25OHD3 concentrations and LV diastolic and end-systolic dimensions. 20 In a population of patients (n = 281), whowere referred to coronary angiography for stable angina pectoris, Akin et al., 21 verified that the LVmass index, the LA diameter, the isovolumic relaxation time and the E’/E ratio were significantly higher in patients with lower levels of 25 (OH)D3 and the authors concluded that serum levels of 25(OH) D are significantly associated with LV diastolic dysfunction and LV mass index. 21 There is growing evidence to support the important role of vitamin D and Fibroblast growth factor 23 (fgf23) hormone in cardiac remodeling. KyB et al. investigated this association and found significant interactions between 25 (0H)D, 1.25 (0H) and FGF23 in cardiac remodeling and, as in other studies already mentioned, the authors found increased LVmass and cavity dilation associated with low 25 (OH)D concentrations and increased FGF23 levels. Both hormones are crucial for an understanding of the role of cardiac remodeling andmay have major therapeutic implications. In addition, LAV increase is described through several pathophysiological mechanisms, which are likewise triggered by reduced LV diastolic and systolic function and SRAA activation. 22 A study carried out by Jorge et al. investigatedwhether VitD deficiency among patients with suspected heart failure with normal ejection fraction had any correlations with systolic and diastolic function markers. Among other results, they found that HFNEF patients had lower serum VitD levels and almost half were VitD deficient. They also noted a negative correlation between VitD and the E/E’ ratio, a LV filling pressure marker. 23 Recently, Aghajani et al., 24 evaluated the longitudinal left ventricular function in patients with coronary artery ectasia (CAE) and vitamin D deficiency by echocardiography. The results showed that LV systolic and diastolic function in patients with CAE and Vitamin D deficiency were impaired. 24 Another study on supplementation showed that D–deficient prediabetic African American males who were treated with high- dose vitamin D2 were found to have attenuated increases in left atrial volume compared with controls over 12-month follow-up. 25 Our ndings are in line with what is described in the literature. We found associations with the parameters that represent diastolic dysfunction, since their stages of incipient dysfunction (assessed on conventional Doppler), until more advanced stages, which include increased filling pressures, using tissue Doppler imaging and parameters that reveal structural changes, notably LAV, which reflects the duration and severity of diastolic dysfunction, obtained from determination of LAV. 26 Based on the results found in our study, themonitoring of Vitamin D levels in the population served by primary health care programs, such as the Médico de Família program, would be helpful in selecting patients at risk of developing cardiovascular changes due to diastolic dysfunction and who should be referred for early echocardiographic evaluation. Conclusion The study of the association between hypovitaminosis D and the development of structural and functional cardiac anomalies can contribute with the discussion about the adoption of a new criterion in the selection of individuals at risk of developing clinical heart failure in primary care. Echocardiography allows for earlydetection of the subclinical condition of cardiac involvement, with prognostic and treatment implications for patients tested for vitamin D status, when the results suggest increased clinical suspicion for diastolic dysfunction. Clinical Application This study shows that Vitamin D nutritional status assessment is justified as a diagnostic method for detecting changes in cardiac structure and function. Even in asymptomatic individuals or under the influence of risk factors, it is possible to detect changes in cardiac remodeling and function, differentiate stage A HF from Macedo et al. Increased left atrial volume Int J Cardiovasc Sci. 2019;32(5):508-516 Original Article