51 research outputs found
Prevalence and risk factors accounting for true silent myocardial ischemia: a pilot case-control study comparing type 2 diabetic with non-diabetic control subjects
<p>Abstract</p> <p>Background</p> <p>Given the elevated risk of cardiovascular events and the higher prevalence of silent coronary artery disease (CAD) in diabetic versus non-diabetic patients, the need to screen asymptomatic diabetic patients for CAD assumes increasing importante. The aims of the study were to assess prospectively the prevalence and risk factor predictors of true silent myocardial ischemia (myocardial perfusion defects in the absence of both angina and ST-segment depression) in asymptomatic type 2 diabetic patients.</p> <p>Methods</p> <p>Stress myocardial perfusion gated SPECT (Single Photon Emission Computed Tomography) was carried out in 41 type 2 diabetic patients without history of cardiovascular disease (CVD) and 41 nondiabetic patients matched by age and gender.</p> <p>Results</p> <p>There were no significant differences between the two groups regarding either the classic CVD risk factors or left ventricular function. True silent ischemia was detected in 21.9% of diabetic patients but only in 2.4% of controls (p < 0.01). The presence of myocardial perfusion defects was independently associated with male gender and the presence of diabetic retinopathy (DR). The probability of having myocardial perfusion defects in an asymptomatic diabetic patient with DR in comparison with diabetic patients without DR was 11.7 [IC95%: 3.7-37].</p> <p>Conclusions</p> <p>True silent myocardial ischemia is a high prevalent condition in asymptomatic type 2 diabetic patients. Male gender and the presence of DR are the risk factors related to its development.</p
Plasma B-type natriuretic peptide levels are poorly related to the occurrence of ischemia or ventricular arrhythmias during symptom-limited exercise in low-risk patients
The usefulness of B-type natriuretic peptide (BNP) as a marker of ischemia is controversial. BNP levels have predicted arrhythmias in various settings, but it is unknown whether they are related to exercise-induced ischemic ventricular arrhythmias. We analyzed in 63 patients (64 ±14 years, 65% male, 62% with known coronary disease) undergoing exercise stress single-photon emission computed tomography (SPECT) the association between plasma BNP values (before and 15 min after exercise) and the occurrence of ischemia or ventricular arrhythmias during the test. Exercise test (8.1 ±2.7 min, 7.4 ±8.1 metabolic equivalents, 82 ±12% of maximal predicted heart rate) induced reversible perfusion defects in 23 (36%) patients. Eight (13%) patients presented significant arrhythmias (≥ 7 ventricular premature complexes/min, couplets, or non-sustained ventricular tachycardia during exercise or in the first minute of recovery). Median baseline BNP levels were 17.5 (12.4-66.4) pg/ml in patients developing scintigraphic ischemia and 45.6 (13.2-107.4) pg/ml in those without ischemia (p = 0.137). The BNP levels increased after exercise (34.4 (15.3-65.4)% increment over baseline, p < 0.001), but the magnitude of this increase was not related to SPECT positivity (35.7 (18.8-65.4)% vs. 27.9 (5.6-64.0)% in patients with and without ischemia, respectively, p = 0.304). No significant association was found between BNP values (at baseline or their change during the test) and ventricular arrhythmias. Plasma BNP values - at baseline or after exercise - were not associated with myocardial ischemia or with ventricular arrhythmia during exercise SPECT. These results highlight the limited usefulness of this biomarker to assess acute ischemia
Valor pronóstico del tamaño del infarto de miocardio cuantificado mediante SPECT gatillada
Objetivos: Evaluar la utilidad de la cuantificación tamaño de infarto (TI) estimado por gated-SPECT en la predicción de complicaciones cardiovasculares en pacientes con un primer infarto agudo de miocardio (IAM). Material y métodos: Se analizaron los pacientes con IAM con elevación del ST desde 2009 a 2014, excluyéndose aquellos con IAM previo. El cálculo de TI se realizó mediante el software Cedars QPS. Se evaluaron eventos al año: insuficiencia cardíaca, arritmias ventriculares, muerte y la combinación de los tres.Resultados: Se incluyeron 149 pacientes, con edad media de 59±11 años y 81,9% de sexo masculino. El 16,1% eran diabéticos y 9,4% presentaron revascularización previa. El 84,6% ingresaron en Killip y Kimbal A, 43% fueron de territorio anterior y 69,8% fueron reperfundidos. La FEVI por gated-SPECT fue del 51±14%. Se realizó seguimiento clínico en el 95,9% de los casos. Se calculó el punto de corte del TI (curva ROC) para predecir eventos combinados al seguimiento en 22% (Sensibilidad: 92%, Especificidad: 81%, ABC: 0,94) y se dividió a la muestra en dos grupos: grupo I (TI<22%) y grupo II (TI≥22%). La prevalencia de eventos combinados fue mayor en el grupo II (2,1% vs. 50%; p<0,001). Se identificó como única variable predictora de eventos al seguimiento al TI ≥22% (OR 1,978; 95% IC 1,887-1,996; p<0,001). Conclusiones: La cuantificación precoz del TI mediante SPECT es un predictor independiente de riesgo al año que permite establecer una estratificación del riesgo en pacientes con un primer IAM
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