Valor pronóstico de la cardiorresonancia magnética de estrés en pacientes ancianos / Prognostic role of stress cardiac magnetic resonance in the elderly

INTRODUCCIÓN Y OBJETIVOS: Diferentes estudios han demostrado el valor diagnóstico y pronóstico de la resonancia magnética cardiaca (RMC) de estrés en pacientes con cardiopatía isquémica. No obstante, la evidencia en ancianos es escasa, en parte por las limitaciones de las técnicas diagnósticas disponibles para esta población. El objetivo de este estudio es evaluar la utilidad de la RMC de estrés en pacientes ancianos. MÉTODOS: Se estudió de manera prospectiva a los pacientes remitidos a una RMC de estrés para descartar isquemia miocárdica. Se consideró paciente anciano a los mayores de 70 años. El estudio de RMC de estrés se realizó conforme a los protocolos internacionales. La gravedad de la hipoperfusión se clasificó en función de los segmentos afectados: ligera (1-2 segmentos), moderada (3-4 segmentos) o grave (> 4 segmentos). Se analizó la aparición de eventos mayores durante el seguimiento (muerte, síndrome coronario agudo o revascularización). La supervivencia se analizó con el método de Kaplan-Meier y un modelo de regresión multivariante de Cox. RESULTADOS: De la cohorte inicial de 333 pacientes, 110 eran mayores de 70 años. En el 40,9% de estos, la RMC de estrés fue positiva para isquemia. La mediana de seguimiento fue de 26 [18-37] meses. En los pacientes ancianos se registraron 35 eventos: 15 fallecimientos, 10 síndromes coronarios agudos y 10 revascularizaciones. Los pacientes con isquemia moderada o grave tenían mayor riesgo de eventos ajustado por edad, sexo y riesgo cardiovascular (HR=3,53; IC95%, 1,41-8,79; p = 0,01). CONCLUSIONES: La presencia de hipoperfusión moderada o grave detectada mediante RMC de estrés predice de manera significativa la aparición de eventos en mayores de 70 años, sin que aparezcan efectos adversos relevantes

INTRODUCTION AND OBJECTIVES: Several trials have tested the diagnostic and prognostic value of stress cardiac magnetic resonance (CMR) in ischemic heart disease. However, scientific evidence is lacking in the older population, and the available techniques have limitations in this population. The aim of this study was to evaluate the usefulness of stress CMR in the elderly. METHODS: We prospectively studied consecutive patients referred for stress CMR to rule out myocardial ischemia. The cutoff age for the elderly population was 70 years. Stress CMR study was performed according to standardized international protocols. Hypoperfusion severity was classified according to the number of affected segments: mild (1-2 segments), moderate (3-4 segments), or severe (> 4 segments). We analyzed the occurrence of major events during follow-up (death, acute coronary syndrome, or revascularization). Survival was studied with the Kaplan-Meier method and multivariate Cox regression models. RESULTS: Of an initial cohort of 333 patients, 110 were older than 70 years. In 40.9% patients, stress CMR was positive for ischemia. The median follow-up was 26 [18-37] months. In elderly patients there were 35 events (15 deaths, 10 acute coronary syndromes, and 10 revascularizations). Patients with moderate or severe ischemia were at a higher risk of events, adjusted for age, sex, and cardiovascular risk (HR, 3.53 [95%CI, 1.41-8.79]; P=.01). CONCLUSIONS: Moderate to severe perfusion defects in stress CMR strongly predict cardiovascular events in people older than 70 years, without relevant adverse effects

Prognostic role of stress cardiac magnetic resonance in the elderly.

INTRODUCTION AND OBJECTIVES: Several trials have tested the diagnostic and prognostic value of stress cardiac magnetic resonance (CMR) in ischemic heart disease. However, scientific evidence is lacking in the older population, and the available techniques have limitations in this population. The aim of this study was to evaluate the usefulness of stress CMR in the elderly. METHODS: We prospectively studied consecutive patients referred for stress CMR to rule out myocardial ischemia. The cutoff age for the elderly population was 70 years. Stress CMR study was performed according to standardized international protocols. Hypoperfusion severity was classified according to the number of affected segments: mild (1-2 segments), moderate (3-4 segments), or severe (> 4 segments). We analyzed the occurrence of major events during follow-up (death, acute coronary syndrome, or revascularization). Survival was studied with the Kaplan-Meier method and multivariate Cox regression models. RESULTS: Of an initial cohort of 333 patients, 110 were older than 70 years. In 40.9% patients, stress CMR was positive for ischemia. The median follow-up was 26 [18-37] months. In elderly patients there were 35 events (15 deaths, 10 acute coronary syndromes, and 10 revascularizations). Patients with moderate or severe ischemia were at a higher risk of events, adjusted for age, sex, and cardiovascular risk (HR, 3.53 [95%CI, 1.41-8.79]; P=.01). CONCLUSIONS: Moderate to severe perfusion defects in stress CMR strongly predict cardiovascular events in people older than 70 years, without relevant adverse effects.

¿Es realmente útil la cardiorresonancia magnética de estrés para detectar isquemia y predecir eventos en pacientes con distinto perfil de riesgo cardiovascular? / Is stress cardiovascular magnetic resonance really useful to detect ischemia and predict events in patients with different cardiovascular risk profile?

Resumen: Objetivo: Evaluar la utilidad diagnóstica y pronóstica de la cardiorresonancia magnética de estrés (RMCE) en pacientes con distinto perfil de riesgo cardiovascular y la importancia del grado de hipoperfusión en la toma de decisiones clínicas. Método: Se analizaron los pacientes sometidos a RMCE con adenosina por sospecha de isquemia miocárdica. Se evaluó su precisión diagnóstica mediante los cocientes de probabilidad (CP) y su valor pronóstico mediante curvas de supervivencia y regresión de Cox. Resultados: Se estudió a 295 pacientes. El CP positivo fue 3.40 y el negativo 0.47. Se demostró una mayor utilidad de la resonancia en: pacientes sin cardiopatía isquémica conocida (CP positivo 4.85); pacientes con dolor torácico atípico (CP positivo 8.56);pacientes con riesgo cardiovascular bajo o intermedio (CP positivo 3.87), y pacientes con hipoperfusión moderada o grave (CP positivo 8.63). Se registraron 60 eventos cardiovasculares mayores. Los pacientes con resultado negativo (p = 0.001) o hipoperfusión leve (p = 0.038) presentaron una supervivencia mayor. En el análisis multivariante, un resultado moderado o grave aumentó la probabilidad de sufrir eventos (hazard ratio [HR] = 2.2; IC 95% 1.26-3.92), sin diferencias entre resultado positivo leve y negativo (HR = 0.93; IC 95% 0.38-2.28). Conclusiones: La RMCE tuvo una mayor utilidad en pacientes con riesgo cardiovascular bajo o intermedio, con dolor torácico atípico, sin cardiopatía isquémica conocida y en aquellos con hipoperfusión moderada o grave. Además, el grado de hipoperfusión fue el principal factor para guiar las decisiones clínicas.

Abstract: Objective: The aim of this study was to evaluate the diagnostic and prognostic usefulness of stress cardiovascular magnetic resonance (stress CMR) in patients with different cardiovascular risk profile and to assess if the degree of hypoperfusion is important to guide clinical decisions. Method: We included patients submitted to adenosine stress CMR to rule out myocardial ischemia. We evaluated its diagnostic accuracy with likelihood ratio (LR) and its prognostic value with survival curves and a Cox regression model. Results: 295 patients were studied. The positive LR was 3.40 and the negative one 0.47. The maximal usefulness of the test was found in patients without previous ischemic cardiomyopathy (positive LR 4.85), patients with atypical chest pain (positive LR 8.56), patients with low or intermediate cardiovascular risk (positive LR 3.87) and those with moderate or severe hypoperfusion (positive LR 8.63). Sixty cardiovascular major events were registered. The best survival prognosis was found in patients with a negative result (p = 0.001) or mild hypoperfusion (p = 0.038). In the multivariate analysis, a moderate or severe hypoperfusion increased cardiovascular event probability (HR = 2.2; IC 95% 1.26-3.92), with no differences between a mild positive and a negative result (HR = 0.93; IC 95% 0.38-2.28). Conclusions: Stress CMR was specially useful in patients with low or intermediate cardiovascular risk, patients with atypical chest pain, patients without previous ischemic cardiomyopathy and those with moderate or severe hypoperfusion. Hypoperfusion degree was the main issue factor to guide clinical decisions.

[Is stress cardiovascular magnetic resonance really useful to detect ischemia and predict events in patients with different cardiovascular risk profile?] / ¿Es realmente útil la cardiorresonancia magnética de estrés para detectar isquemia y predecir eventos en pacientes con distinto perfil de riesgo cardiovascular?

OBJECTIVE: The aim of this study was to evaluate the diagnostic and prognostic usefulness of stress cardiovascular magnetic resonance (stress CMR) in patients with different cardiovascular risk profile and to assess if the degree of hypoperfusion is important to guide clinical decisions. METHOD: We included patients submitted to adenosine stress CMR to rule out myocardial ischemia. We evaluated its diagnostic accuracy with likelihood ratio (LR) and its prognostic value with survival curves and a Cox regression model. RESULTS: 295 patients were studied. The positive LR was 3.40 and the negative one 0.47. The maximal usefulness of the test was found in patients without previous ischemic cardiomyopathy (positive LR 4.85), patients with atypical chest pain (positive LR 8.56), patients with low or intermediate cardiovascular risk (positive LR 3.87) and those with moderate or severe hypoperfusion (positive LR 8.63). Sixty cardiovascular major events were registered. The best survival prognosis was found in patients with a negative result (p=0.001) or mild hypoperfusion (p=0.038). In the multivariate analysis, a moderate or severe hypoperfusion increased cardiovascular event probability (HR=2.2; IC 95% 1.26-3.92), with no differences between a mild positive and a negative result (HR=0.93; IC 95% 0.38-2.28). CONCLUSIONS: Stress CMR was specially useful in patients with low or intermediate cardiovascular risk, patients with atypical chest pain, patients without previous ischemic cardiomyopathy and those with moderate or severe hypoperfusion. Hypoperfusion degree was the main issue factor to guide clinical decisions.

Association of low GLP-1 with oxidative stress is related to cardiac disease and outcome in patients with type 2 diabetes mellitus: a pilot study.

Oxidative stress (OS) contributes to cardiovascular damage in type 2 diabetes mellitus (T2DM). The peptide glucagon-like peptide-1 (GLP-1) inhibits OS and exerts cardiovascular protective actions. Our aim was to investigate whether cardiac remodeling (CR) and cardiovascular events (CVE) are associated with circulating GLP-1 and biomarkers of OS in T2DM patients. We also studied GLP-1 antioxidant effects in a model of cardiomyocyte lipotoxicity. We examined 72 T2DM patients with no coronary or valve heart disease and 14 nondiabetic subjects. A median of 6 years follow-up information was obtained in 60 patients. Circulating GLP-1, dipeptidyl peptidase-4 activity, and biomarkers of OS were quantified. In T2DM patients, circulating GLP-1 decreased and OS biomarkers increased, compared with nondiabetics. Plasma GLP-1 was inversely correlated with serum 3-nitrotyrosine in T2DM patients. Patients showing high circulating 3-nitrotyrosine and low GLP-1 levels exhibited CR and higher risk for CVE, compared to the remaining patients. In palmitate-stimulated HL-1 cardiomyocytes, GLP-1 reduced cytosolic and mitochondrial oxidative stress, increased mitochondrial ATP synthase expression, partially restored mitochondrial membrane permeability and cytochrome c oxidase activity, blunted leakage of creatine to the extracellular medium, and inhibited oxidative damage in total and mitochondrial DNA. These results suggest that T2DM patients with reduced circulating GLP-1 and exacerbated OS may exhibit CR and be at higher risk for CVE. In addition, GLP-1 exerts antioxidant effects in HL-1 palmitate-overloaded cardiomyocytes. It is proposed that therapies aimed to increase GLP-1 may counteract OS, protect from CR, and prevent CVE in patients with T2DM.

The activity of circulating dipeptidyl peptidase-4 is associated with subclinical left ventricular dysfunction in patients with type 2 diabetes mellitus.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) present subclinical left ventricular systolic and/or diastolic dysfunction (LVD). Dipeptidyl peptidase-4 (DPP4) inactivates peptides that possess cardioprotective actions. Our aim was to analyze whether the activity of circulating DPP4 is associated with echocardiographically defined LVD in asymptomatic patients with T2DM. METHODS: In this cross-sectional study, we examined 83 T2DM patients with no coronary or valve heart disease and 59 age and gender-matched non-diabetic subjects. Plasma DPP4 activity (DPP4a) was measured by enzymatic assay and serum amino-terminal pro-brain natriuretic peptide (NT-proBNP) was measured by enzyme-linked immunosorbent assay. LV function was assessed by two-dimensional echocardiographic imaging, targeted M-mode recordings and Doppler ultrasound measurements. Differences in means were assessed by t-tests and one-way ANOVA. Associations were assessed by adjusted multiple linear regression and logistic regression analyses. RESULTS: DPP4a was increased in T2DM patients as compared with non-diabetic subjects (5855 ± 1632 vs 5208 ± 957 pmol/min/mL, p < 0.05). Clinical characteristics and echocardiographic parameters assessing LV morphology were similar across DPP4a tertiles in T2DM patients. However, prevalence of LVD progressively increased across incremental DPP4a tertiles (13%, 39% and 71%, all p < 0.001). Multivariate regression analysis confirmed the independent associations of DPP4a with LVD in T2DM patients (p < 0.05). Similarly, multiple logistic regression analysis showed that an increase of 100 pmol/min/min plasma DPP4a was independently associated with an increased frequency of LVD with an adjusted odds ratio of 1.10 (95% CI, 1.04 to 1.15, p = 0.001). CONCLUSIONS: An excessive activity of circulating DPP4 is independently associated with subclinical LVD in T2DM patients. Albeit descriptive, these findings suggest that DPP4 may be involved in the mechanisms of LVD in T2DM.

Randomized clinical trial on acute effects of i.v. iron sucrose during haemodialysis.

AIM: Haemodialysis induces endothelial dysfunction by oxidation and inflammation. Intravenous iron administration during haemodialysis could worsen endothelial dysfunction. The aim of this study was to ascertain if iron produces endothelial dysfunction and the possible neutralizing effect of N-acetylcysteine when infused before iron. The oxidative and inflammatory effects of iron during haemodialysis were also assessed. METHODS: Forty patients undergoing haemodialysis were studied in a randomized and cross-over design with and without N-acetylcysteine infused before iron sucrose (50 or 100 mg). Plasma Von Willebrand factor (vWF), soluble intercellular adhesion molecule-1 (sICAM-1) levels, malondialdehyde, total antioxidant capacity, CD11b/CD18 expression in monocytes, interleukin (IL)-8 in monocytes and plasma IL-8 were studied at baseline and during haemodialysis. RESULTS: Haemodialysis produced significant (P < 0.001) increase in plasma vWF, sICAM-1, malondialdehyde, IL-8 and CD11b/CD18 expression in monocytes, as well as decrease in total antioxidant capacity. Iron induced significant increase in plasma malondialdehyde and IL-8 in monocytes, but had no effect on total antioxidant capacity, CD11b/CD18 expression, plasma IL-8, vWF and sICAM-1. The addition of N-acetylcysteine to 50 mg of iron produced a significant (P = 0.040) decrease in malondialdehyde. CONCLUSION: Standard (100 mg) and low (50 mg) doses of iron during haemodialysis had no effects on endothelium. Iron only had minor effects on inflammation and produced an increase in oxidative stress, which was neutralized by N-acetylcysteine at low iron dose. Haemodialysis caused a significant increase in oxidative stress, inflammation and endothelial dysfunction markers.

Characterization of coronary plaques with combined use of intravascular ultrasound, virtual histology and optical coherence tomography.

According to post-mortem studies, luminal thrombosis occurs from plaque rupture, erosion and calcified nodules. In vivo studies have found thin cap fibroatheroma (TCFA) as the main vulnerable lesion, prone to rupture. Few data about other post-mortem lesions have been reported in vivo. Our main objective is to characterize in vivo the coronary plaques with intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT), in order to detect not only thin cap fibroatheroma (TCFA), but also other possible vulnerable lesions. The secondary objective is to correlate these findings with clinical and analytical data. Twenty-five patients (18 stable) submitted to coronary angiography were included in this pilot study. After angiography, the three vessels were studied (when possible) with IVUS-VH and OCT. Plaque characteristics were correlated with clinical and analytical data. Forty-six lesions were analyzed. IVUS-VH detected significant necrotic core in 15 (3 were definite TCFA). OCT detected TCFA in 10 lesions, erosion in 6, thrombus in 5 and calcified nodule in 8. Possible vulnerable lesion was found in 61% of stable and 57% of unstable patients. Erosions and calcified nodules were only found in stable patients. Those with significant necrotic core had higher body mass index (P=0.016), higher levels of hs-CRP (P=0.019) and triglycerides (P=0.040). The higher the levels of hs-CRP, the larger the size of the necrotic core (r=0.69, P=0.003). Lesions with characteristics of vulnerability were detected by IVUS-VH and OCT in more than 50% of stable and unstable coronary patients. A significant necrotic core was mainly correlated with higher hs-CRP.

Echocardiographic findings and NT-proBNP level in type-2 diabetic patients with and without ischemic heart disease.

The aim of this study was to determine whether there are differences in echocardiographic findings or in the level of a biochemical marker (i.e. N-terminal probrain natriuretic peptide [NT-proBNP]) between controls and type-2 diabetic patients with or without ischemic heart disease. Echocardiography was used to assess left ventricular function and morphology. In addition, the plasma NT-proBNP concentration was measured. The prevalence of diastolic dysfunction was greater in diabetics without ischemic heart disease than in controls (88% vs. 74%, respectively; P< .001) and the NT-proBNP concentration was higher (350.6+/-197.8 vs. 281.7+/-190.4 fmol/mL; P< .001). Diabetics with ischemic heart disease had a higher NT-proBNP concentration than those without (720.4+/-278.1 vs. 350.6+/-197.8 fmol/mL, respectively; P< .001). An NT-proBNP concentration >490 fmol/mL had a sensitivity of 84% and a specificity of 75% for detecting ischemic heart disease in diabetics.

Estudio ecocardiográfico y de la concentración de NT-proBNP en pacientes diabéticos tipo 2 con y sin cardiopatía isquémica / Echocardiographic findings and NT-proBNP level in type-2 diabetic patients with and without ischemic heart disease

El objetivo de este trabajo es analizar posibles diferencias ecocardiográficas y bioquímicas (NT-proBNP) entre controles y pacientes diabéticos tipo 2 sin cardiopatía isquémica y con ella. El estudio ecocardiográfico comprendió la forma y la función ventricular izquierda. Además se determinaron las concentraciones plasmáticas de NT-proBNP. Los diabéticos sin cardiopatía isquémica presentaron mayor prevalencia de disfunción diastólica (el 88 frente al 74%; p < 0,001) y mayor concentración de NT-proBNP (350,6 ± 197,8 frente a 281,7 ± 190,4 fmol/ ml; p < 0,001) que los controles. Los diabéticos con cardiopatía isquémica mostraron concentraciones de NT-proBNP muy superiores a las de los diabéticos sin cardiopatía isquémica (720,4 ± 278,1 frente a 350,6 ± 197,8 fmol/ml respectivamente; p < 0,001). Una concentración de NT-proBNP > 490 fmol/ml tuvo el 84% de sensibilidad y el 75% de especificidad para detectar cardiopatía isquémica en pacientes diabéticos (AU)

The aim of this study was to determine whether there are differences in echocardiographic findings or in the level of a biochemical marker (i.e. N-terminal probrain natriuretic peptide [NT-proBNP]) between controls and type-2 diabetic patients with or without ischemic heart disease. Echocardiography was used to assess left ventricular function and morphology. In addition, the plasma NT-proBNP concentration was measured. The prevalence of diastolic dysfunction was greater in diabetics without ischemic heart disease than in controls (88% vs. 74%, respectively; P < .001) and the NT-proBNP concentration was higher (350.6±197.8 vs. 281.7±190.4 fmol/mL; P < .001). Diabetics with ischemic heart disease had a higher NT-proBNP concentration than those without (720.4±278.1 vs. 350.6±197.8 fmol/mL, respectively; P < .001). An NT-proBNP concentration >490 fmol/mL had a sensitivity of 84% and a specificity of 75% for detecting ischemic heart disease in diabetics (AU)

Increased thrombin generation after acute versus chronic coronary disease as assessed by the thrombin generation test.

Atherosclerosis is the most common pathophysiologic substrate of coronary artery disease (CAD). Whereas plaque progression and arterial remodeling are critical components in chronic CAD, intracoronary thrombosis over plaque disruption is causally related to acute CAD. It was the objective of this study to investigate the differences between prior acute CAD and chronic CAD by a simple global coagulation assay measuring thrombin generation. A cross-sectional study involving 15 healthy controls, 35 patients with chronic stable CAD, and 60 patients after an episode of acute myocardial infarction (AMI) was performed. Thrombin generation was measured between three and 11 months after the initial diagnosis (mean 6 months) by a commercially available fluorogenic assay (Technothrombin TGA). In each patient the lag phase, velocity index and peak thrombin were obtained from the thrombogram profile. Traditional cardiovascular risk factors were recorded, and the inflammatory markers, fibrinogen and hs-C-reactive protein were determined. Compared with stable CAD patients, showing normal thrombograms, those with previous AMI showed earlier lag phase (p < 0.05) and significant increase of both the velocity index (p < 0.001) and peak thrombin (p < 0.05), indicating faster and higher thrombin generation in the AMI group. Differences in thrombin generation between stable and acute CAD patients remained significant (p < 0.001) after adjusting for conventional CAD risk factors (age, gender, diabetes, hypertension, smoking, and hypercholesterolemia). In conclusion, patients with a previous history of acute CAD showed earlier, faster and higher thrombin generation than stable chronic CAD patients. The thrombin generation test may be of clinical value to monitor hypercoagulable/vulnerable blood and/or guide therapy in CAD.

Papel de la gated-SPECT frente a otras técnicas de imagen en cardiología / Comparison of gated SPECT with other imaging techniques used in cardiology

Para el diagnóstico y la evaluación pronóstica de los pacientes con cardiopatía isquémica, además de la gated-SPECT se utilizan otras técnicas de imagen, como la ecocardiografía con sobrecarga, la tomografía computarizada (TC) y la resonancia magnética (RM). La ecocardiografía con sobrecarga (ejercicio físico o sobrecarga farmacológica) es la más utilizada por el momento, dada su gran disponibilidad, inocuidad y versatilidad. Esta técnica tiene un valor parecido al de la gated-SPECT para detectar isquemia, con una menor sensibilidad y una mayor especificidad. La TC puede usarse para detectar calcio, que mide la carga aterosclerótica total, pero no el grado de obstrucción coronaria, ya que las placas más calcificadas no necesariamente son las más obstructivas. A mayor cantidad de calcio, mayor probabilidad de lesiones coronarias importantes y peor pronóstico. La TC también puede usarse como angiografía no invasiva, si se inyecta contraste yodado y se hace una reconstrucción posterior de las arterias coronarias, tanto de forma longitudinal como transversal. Con los equipos habituales se necesita bradicardizar al paciente con un betabloqueante y no se puede hacer un buen estudio si hay cualquier tipo de arritmia. La RM con gadolinio permite detectar infartos no transmurales con una alta fiabilidad. Además, facilita la evaluación completa de la anatomía y la función ventricular, así como los estudios de sobrecarga farmacológica para la detección de isquemia. Los principales problemas son su elevado coste y su menor disponibilidad respecto a las otras técnicas. La tomografía por emisión de positrones (PET) se emplea de momento en investigación y muy poco en la clínica (AU)

In addition to gated SPECT, a number of other imaging techniques are used in the diagnostic and prognostic assessment of patients with ischemic heart disease, such as stress echocardiography, computed tomography, and magnetic resonance imaging. At present, stress echocardiography (involving physical exercise or pharmacological stress) is the most commonly used technique because it is readily available, safe and versatile. This technique is as valuable as gated SPECT for detecting ischemia, and has lower sensitivity and higher specificity. Computed tomography (CT) can be used to detect calcium, thereby giving an estimate of the total atherosclerotic burden, but not of the degree of coronary obstruction, because the most calcified plaques are not necessarily the most obstructive. However, the greater the amount of calcium, the higher the probability that severe coronary lesions are present and the worse the prognosis. In addition, CT can also be used as a form of noninvasive angiography. Following the injection of iodine contrast, the anatomy of the coronary arteries can be reconstructed, both longitudinally and transversally. With currently available systems, it is necessary to administer a betablocker to induce bradycardia as the presence of any form of arrhythmia can prevent accurate imaging. Magnetic resonance imaging (MRI) with gadolinium can detect non-transmural infarctions with great accuracy. Moreover, it can also provide a complete assessment of ventricular anatomy and function, and can be used to detect ischemia during pharmacological stress. The main disadvantages are that it is expensive and that it is less readily available than other techniques. Currently, positron-emission tomography (PET) is mainly a research tool and is very seldom used clinically (AU)

Recomendaciones sobre las indicaciones clínicas de la gated-SPECT de perfusión miocárdica / Recommendations on clinical indications for myocardial perfusion gated SPECT

Desde 1999 no se había realizado ninguna revisión de las Guías de actuación clínica de la Sociedad Española de Cardiología en Cardiología Nuclear, por lo que en este artículo exponemos las indicaciones clase I y IIa de la American College of Cardiology/American Heart Association/American Society of Nuclear Cardiology (ACC/AHA/ASNC) con nivel de evidencia A o B, junto con las 27 indicaciones consideradas adecuadas por el Comité de expertos de la American College of Cardiology Foundation/American Society of Nuclear Cardiology (ACCF/ASNC) y los comentarios que hemos considerado oportuno añadir los firmantes de este artículo (AU)

The Spanish Society of Cardiology's Clinical Practice Guidelines on Nuclear Cardiology have not been revised since 1999. Correspondingly, this article describes the class-I and class-IIa indications of the American College of Cardiology (ACC)/American Heart Association (AHA)/American Society for Nuclear Cardiology (ASNC), which have a grade-A or grade-B level of supporting evidence. In addition, details are given of the 27 appropriateness criteria of the American College of Cardiology Foundation (ACCF)/ASNC expert committee, along with additional comments which the authors of this review thought were appropriate to make at this time (AU)

A case of capecitabine-induced coronary microspasm in a patient with rectal cancer.

5-Fluorouracil (5-FU) is the most frequently used chemotherapy agent concomitant with radiotherapy in the management of patients with rectal cancer. Capecitabine is an oral fluoropyrimidine that mimics the pharmaconkinetics of infusional 5-FU. This new drug is replacing 5-FU as a part of the combined-modality treatment of a number of gastrointestinal cancers. While cardiac events associated with the use of 5-FU are a well known side effect, capecitabine-induced cardiotoxicity has been only rarely reported. Here, we reviewed the case of a patient with rectal cancer who had a capecitabine-induced coronary vasospasm. The most prominent mutation of the dihydropyrimidine dehydrogenase gene was also analyzed.

Variability in individual responsiveness to aspirin: clinical implications and treatment.

Aspirin protects from cardiovascular events because of its antiaggregant effect. The occurrence of new events in patients who take aspirin has been called clinical aspirin resistance. Many authors believe that aspirin resistance must be detected by biochemical tests, although there is no agreement on which is the best. Nor is there agreement on the term aspirin resistance. Tests used in research laboratories are aggregometry (turbidometric and impedance), tests based on activation-dependent changes in platelet surface, and tests based on activation-dependent release from platelets. Point-of-care tests are PFA-100, IMPACT and VerifyNow, which can detect platelet dysfunction that may be due to aspirin effect, but their use for this purpose is not yet recommended. Aspirin response may be modified by different factors: patient's compliance, dose, smoking, hyperlipidemia, hyperglucemia, acute coronary syndrome, percutaneous revascularization, recent stroke, extracorporeal circulation, heart failure, exercise, circadian rhythm, absorption, concomitant medications, polymorphisms. Patients with aspirin resistance may have an increased risk of cardiovascular events, and possible therapeutic options are to increase the dosage, to replace aspirin with another antiaggregant drug or to add another drug. In conclusion, there are many reasons that explain the variability in individual responsiveness to aspirin. The term resistance is probably not exact in describing this phenomenon.

Myocardial perfusion imaging with adenosine triphosphate predicts the rate of cardiovascular events.

BACKGROUND: Adenosine triphosphate (ATP) has effects similar to adenosine, including a very short half-life, with the advantage of a much lower cost. Our aim was to evaluate whether myocardial single photon emission computed tomography (SPECT) with ATP can predict the rate of hard events. METHODS AND RESULTS: We studied 299 patients (188 men; mean age, 64 +/- 10 years) with known or suspected coronary disease with thallium 201 SPECT during ATP infusion and at rest. Perfusion defects were divided into the following: absent/mild reversible, moderate/severe reversible, and mixed/fixed. During a maximum follow-up of 87 months (mean, 32.7 +/- 20.3 months), the rate of cardiovascular events was studied. The prognostic value of different variables that can influence survival was calculated with the Cox proportional hazards model. The total number of cardiovascular events was 115 (43 hard events). The annual rate of hard events according to type of perfusion defect was 3.44% (95% confidence interval [CI], 2.12-5.26) for absent/mild reversible, 6.06% (95% CI, 2.23-13.20) for moderate/severe reversible, and 15.12% (95% CI, 8.64-24.55) for mixed/fixed. In the Cox model the variables that significantly predicted hard events were age greater than 55 years (P = .0293), diabetes (P = .0036), and severe perfusion defects (P = .0008). CONCLUSION: ATP can be used for pharmacologic stress testing. SPECT with ATP has a stronger correlation with the rate of hard events than clinical variables.

Relación entre mortalidad por infarto agudo de miocardio y cumplimiento de las guías de práctica clínica / Relationship between mortality due to acute myocardial infarction and adherence to clinical guidelines

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Ergonovine test in angina with normal coronary arteries. Is it worth doing it?

BACKGROUND: Patients with angina and normal coronary arteries are often misdiagnosed with having non-cardiac pain. Although vasospasm is a well-known entity, spasm provocation is not routinely done in the majority of hospitals at present. MATERIALS AND METHODS: One hundred and sixty two consecutive patients with thoracic pain and normal coronary arteries were retrospectively studied. The characteristics of pain were analysed. One hundred and sixty one non-invasive tests (with and without imaging) were done to 126 patients before angiography. Increasing doses of ergonovine (from 1 to 30 microg) were injected into the coronary arteries to provoke coronary spasm. The correlation between ergonovine-induced spasm and non-invasive tests was studied. RESULTS: Oppressive thoracic pain suggestive of angina was present in 144 patients. It occurred at rest in 59 patients, only at night in 14, with effort in 40, and it was mixed in 31. Non-oppressive atypical pain was reported by 18 patients. Non-invasive tests were 94 positive, 60 negative and 7 non-diagnostic. Ergonovine test elicited coronary spasm in 85 patients (52.5%). No significant correlation was found between the positivity of a non-invasive test and ergonovine-induced spasm. CONCLUSIONS: More than half of the patients with angina and normal coronary arteries can be diagnosed with vasospastic angina if ergonovine test is performed. Even patients with a negative non-invasive test maybe sent to coronary angiography when vasospastic angina is suspected, in order to have an accurate diagnosis.

[Neurohormones and cytokines in heart failure. Correlation with coronary flow reserve]. / Neurohormonas y citocinas en la insuficiencia cardíaca. Correlación con la reserva de flujo coronario.

INTRODUCTION AND OBJECTIVES: In heart failure, the coronary flow reserve (CFR) measured by positron-emission tomography (PET) is reduced. As neurohormone and cytokine levels are also altered in patients with the condition, our aim was to determine whether there is a correlation between CFR and neurohormone and cytokine levels. PATIENTS AND METHOD: The study included 40 patients with heart failure but without ischemic heart disease. Myocardial blood flow was measured by PET using nitrogen-13 ammonia at baseline and during ATP infusion. The CFR was calculated for each patient. In addition, levels of the following were determined: norepinephrine, endothelin-1, angiotensin-II, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), tumor necrosis factor-alpha, interleukin (IL)-1beta, soluble IL-2 receptor, and IL-6. RESULTS: All neurohormone levels were elevated above reference values. The levels of all cytokines, except IL-1beta, were also elevated. There was a significant negative correlation between CFR and the levels of several neurohormones: ANP (r=-0.476), BNP (r=-0.442), and IL-6 (r=-0.509). CONCLUSIONS: In heart failure, the decrease in CFR is correlated with increases in the levels of certain neurohormones (i.e., ANP and BNP) and cytokines (i.e., IL-6), with vasodilatory effect. These increases are probably are related to compensatory mechanisms that are unable to correct for the endothelial dysfunction present in these patients.