Echocardiography / Prospective studies / Humans / Female / Male / Risk factors / Middle Aged / Heart valves / Infective Endocarditis / Myocardium / Public health systems and services research / Risk Factors / Sensitivity and Specificity / Prospective Study / Predictive value of tests / Cohort Studies / The American / Risk factors / Middle Aged / Heart valves / Infective Endocarditis / Myocardium / Public health systems and services research / Risk Factors / Sensitivity and Specificity / Prospective Study / Predictive value of tests / Cohort Studies / The American