[Primary PCI in ST-elevation myocardial infarction: mode of referral and time to PCI]. / ICP primária no enfarte de miocárdio com supradesnivelamento do segmento ST: tempo para intervenção e modos de referenciação.

INTRODUCTION: According to the current guidelines for treatment of ST-elevation myocardial infarction (STEMI), percutaneous coronary intervention (PCI) should be performed within 90 min of first medical contact and total ischemic time should not exceed 120 min. The aim of this study was to analyze compliance with STEMI guidelines in a tertiary PCI center. METHODS: This was a prospective single-center registry of 223 consecutive STEMI patients referred for primary PCI between 2003 and 2007. RESULTS: In this population (mean age 60±12 years, 76% male), median total ischemic time was 4h 30 min (<120 min in 4% of patients). The interval with the best performance was first medical contact to first ECG (median 8 min, <10 min in 59% of patients). The worst intervals were symptom onset to first medical contact (median 104 min, <30 min in 6%) and first ECG to PCI (median 140 min, <90 min in 16%). Shorter total ischemic time was associated with better post-PCI TIMI flow, TIMI frame count and ST-segment resolution (p<0.03). The three most common patient origins were two nearby hospitals (A and B) and the pre-hospital emergency system. The pre-hospital group had shorter total ischemic time than patients from hospitals A or B (2h 45 min vs. 4h 44 min and 6h 40 min, respectively, p<0.05), with shorter door-to-balloon time (89 min vs. 147 min and 146 min, respectively, p<0.05). CONCLUSIONS: In this population, only a small proportion of patients with acute myocardial infarction underwent primary PCI within the recommended time. Patients referred through the pre-hospital emergency system, although a minority, had the best results in terms of early treatment. Compliance with the guidelines translates into better myocardial perfusion achieved through primary PCI.

Percutaneous revascularization strategies in saphenous vein graft lesions: long-term results.

AIMS: Although half of saphenous vein grafts (SVGs) present obstructive atherosclerotic disease 10 years after implantation, controversy remains concerning the ideal treatment. Our aim was to compare percutaneous revascularization (PCI) options in SVG lesions, according to intervention strategy and type of stent. METHODS: A retrospective single-center analysis selected 618 consecutive patients with previous bypass surgery who underwent PCI between 2003 and 2008. Clinical and angiographic parameters were analyzed according to intervention strategy - PCI in SVG vs. native vessel vs. combined approach - and type of stent implanted - drug-eluting (DES) vs. bare-metal (BMS) vs. both. A Cox regressive analysis of event-free survival was performed with regard to the primary outcomes of death, myocardial infarction (MI) and target vessel failure (TVF). RESULTS: During a mean follow-up of 796±548 days the rates of death, MI and TVF were 10.9%, 10.5% and 29.5%, respectively. With regard to intervention strategy (74.4% of PCI performed in native vessels, 17.2% in SVGs and 8.4% combined), no significant differences were seen between groups (death p=0.22, MI p=0.20, TVF p=0.80). The type of stents implanted (DES 83.2%, BMS 10.2%, both 3.2%) also did not influence long-term prognosis (death p=0.09, MI p=0.11, TVF p=0.64). The implantation of DES had a favorable impact on survival (p<0.001) in the subgroup of patients treated in native vessels but not in SVG. CONCLUSIONS: Among patients with SVG lesions, long-term mortality, MI and TVF were not affected by intervention options, except for the favorable impact on survival of DES in patients treated in native vessels.

[NT-proBNP for risk stratification of pulmonary embolism]. / NT-proBNP na estratificação de risco no tromboembolismo pulmonar.

INTRODUCTION: Pulmonary embolism (PE) is an entity with high mortality and morbidity, in which risk stratification for adverse events is essential. N-terminal brain natriuretic peptide (NT-proBNP), a right ventricular dysfunction marker, may be useful in assessing the short-term prognosis of patients with PE. AIMS: To characterize a sample of patients hospitalized with PE according to NT-proBNP level at hospital admission and to assess the impact of this biomarker on short-term evolution. METHODS: We performed a retrospective analysis of consecutive patients admitted with PE over a period of 3.5 years. Based on the median NT-proBNP at hospital admission, patients were divided into two groups (Group 1: NT-proBNP

[Successful cardiac resynchronization therapy in a patient with heart failure and ischemic mitral regurgitation: importance of septal flash]. / Sucesso da terapêutica de ressincronização cardíaca num doente com insuficiência cardíaca e regurgitação mitral secundária a doença isquémica: importância do septal flash.

We describe the case of a 76-year-old man with a history of ischemic heart disease and functional mitral regurgitation who over the previous six months had experienced worsening of functional class (NYHA III/IV) under optimal medical therapy, without ischemic symptoms and with negative ischemic tests. Mitral valve annuloplasty was considered. As the patient presented left bundle branch block on the surface ECG, cardiac resynchronization therapy (CRT) was also considered. There was, however, severe biventricular dysfunction and moderate to severe pulmonary hypertension, which are considered predictors of non-response to CRT. On echocardiographic evaluation of mechanical dyssynchrony by two-dimensional strain (2DS), spectral Doppler and color tissue Doppler imaging (TDI)/tissue synchronization imaging (TSI), we observed absence of atrioventricular dyssynchrony and presence of interventricular dyssynchrony, with inconclusive intraventricular longitudinal dyssynchrony, but with marked intraventricular radial dyssynchrony. The latter, immediately observed on the two-dimensional image, and termed multiphasic septal motion or septal flash, was characterized and quantified with 2DS. In our experience, the presence of such septal motion, for which the substrate is predominantly radial dyssynchrony, is a predictor of CRT response. Weighing the risks and benefits of mitral valve annuloplasty without associated revascularization versus CRT, we opted for the latter. Marked improvement in clinical and echocardiographic parameters was observed, compatible with the current criteria for "responder". The improvement began one month after implantation and continued throughout two-year follow-up. In this case, detailed echocardiographic study of mechanical synchrony enabled the most appropriate and effective therapeutic strategy to be chosen.

Does continuous ST-segment monitoring add prognostic information to the TIMI, PURSUIT, and GRACE risk scores?

BACKGROUND: Recurrent ischemia is frequent in patients with non-ST-elevation acute coronary syndromes (NST-ACS), and portends a worse prognosis. Continuous ST-segment monitoring (CSTM) reflects the dynamic nature of ischemia and allows the detection of silent episodes. The aim of this study is to investigate whether CSTM adds prognostic information to the risk scores (RS) currently used. METHODS: We studied 234 patients with NST-ACS in whom CSTM was performed in the first 24 hours after admission. An ST episode was defined as a transient ST-segment deviation in ≥1 lead of ≥ 0.1 mV, and persisting ≥1 minute. Three RS were calculated: Thrombolysis in Myocardial Infarction (TIMI; for NST-ACS), Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Supression Using Integrilin (PURSUIT; death/MI model), and Global Registry of Acute Coronary Events (GRACE). The end point was defined as death or nonfatal myocardial infarction (MI), during 1-year follow-up. RESULTS: ST episodes were detected in 54 patients (23.1%) and associated with worse 1-year outcome: 25.9% end point rate versus 12.2% (Odds Ratio [OR]= 2.51; 95% Confidence Interval [CI], 1.18-5, 35; P = 0.026). All three RS predicted 1-year outcome, but the GRACE (c-statistic = 0.755; 95% CI, 0.695-0.809) was superior to both TIMI (c-statistic = 0.632; 95% CI, 0.567-0.694) and PURSUIT (c-statistic = 0.644; 95% CI: 0.579-0.706). A GRACE RS > 124 showed the highest accuracy for predicting end point. The presence of ST episodes added independent prognostic information the TIMI RS (hazard ratio [HR]= 2.23; 95% CI, 1.13-4.38) and to PURSUIT RS (HR = 2.03; 95% CI, 1.03-3.98), but not to the GRACE RS. CONCLUSIONS: CSTM provides incremental prognostic information beyond the TIMI and PURSUIT RS, but not the GRACE risk score. Hence, the GRACE risk score should be the preferred stratification model in daily practice.

Cardiac resynchronization therapy: can left ventricular lead position make the difference?

The authors report the case of an 82-year-old female patient with non-ischemic dilated cardiomyopathy who developed worsening heart failure functional class despite optimal medical therapy. As the patient met criteria for cardiac resynchronization, a CRT-P device was implanted, but due to technical difficulties, the left ventricular lead was implanted in the anterior coronary vein. In the absence of any benefit from the procedure, a new left ventricular lead was implanted in posterolateral position with good clinical and echocardiographic response.

Left atrial volume calculated by multi-detector computed tomography may predict successful pulmonary vein isolation in catheter ablation of atrial fibrillation.

AIMS: Catheter ablation (CA) of atrial fibrillation (AF) might be a definitive curative therapy for selected groups of patients (pts). However, current ablation protocols are not standardized and predictors of CA success and sinus rhythm maintenance are not clearly defined. To evaluate whether left atrium (LA) volume quantification provided by multi-detector computed tomography (MDCT) might predict the success of pulmonary vein (PV) isolation procedure. METHODS AND RESULTS: We evaluated 99 pts, 66 male, mean age 54.4 +/- 10.1 years, referred for CA because of drug resistant AF. All pts were submitted to 64-slice MDCT scan for electroanatomic mapping integration, pulmonary veins anatomy delineation, LA thrombi exclusion, and LA volume estimation. Complete isolation of all the PVs was always performed with eventual cavo-tricuspid isthmus ablation. For a mean follow-up period (Fup) of 16.7 +/- 6.6 months, clinical success was assessed after a 3-month blanking period. Anti-arrhythmic drug therapy was discontinued or modified at the clinician's criteria. At the end of the Fup, 29 pts suspended anti-arrhythmic drug therapy and 26% were of oral anticoagulation. Univariate analysis showed that the probability of AF relapse after CA was higher in pts with non-paroxysmal forms of AF. The probability of relapse was significantly higher in pts with LA volumes greater than 100 mL when assessed by MDCT. We found that the LA volume of 145 mL was a good cut-off value for AF recurrence prediction. Patients with LA volumes greater than 145 mL had significantly higher recurrence rates of arrhythmia, even when adjusted for the effect of age, gender, body mass index, hypertension, and type of AF. CONCLUSION: Left atrium volume estimated by MDCT may be useful to identify pts in whom successful AF ablation can be achieved with simpler ablation procedures, restricted to PV isolation.

Atrial fibrillation ablation: importance of cavotricuspid isthmus block.

INTRODUCTION AND OBJECTIVE: Maintenance of atrial fibrillation (AF) depends on the presence of multiple reentrant circuits in the atria. In AF ablation, after pulmonary vein (PV) isolation, substrate modification can be increased by performing linear lesions in the left atrium that reduce the fibrillatory surface. A cavotricuspid isthmus (CTI) block may be an easier and safer alternative to left atrial lines for this purpose. Non-inducibility after AF ablation is associated with a higher success rate. The aim of this study is to assess whether CTI ablation after PV isolation reduces inducibility of atrial arrhythmias, particularly AF. METHODS AND RESULTS: In 29 consecutive patients (23 male, mean age 54.6+/-11.4 years, 11 (38%) with hypertension and four (14%) with structural heart disease, mean left atrial dimension 43+/-6 mm) undergoing PV isolation for paroxysmal or persistent AF, atrial arrhythmia inducibility was tested before and after CTI ablation. The procedure was performed using a CARTO-Merge mapping system, one or two Lasso catheters, an irrigated ablation catheter and radiofrequency energy. Atrial arrhythmia inducibility was tested with burst pacing down to 150 ms or atrial refractoriness from the proximal coronary sinus. Atrial arrhythmias were considered inducible if they persisted for more than 60 seconds. Of the 29 patients, 26 (90%) had an inducible arrhythmia before CTI ablation--AF in 16, typical atrial flutter (AFL) in seven and atypical AFL in three. Three (10%) were non-inducible. After CTI ablation, only 11 patients (38%) maintained arrhythmia inducibility (p<0.001)--AF in nine and atypical AFL in two. There was a significant reduction of AF inducibility (16 vs. 9/29, p=0.016) and of combined AF and atypical AFL inducibility (19 vs. 11/29, p=0.021). After one year of follow-up, 23 patients (79%) had no recurrence of arrhythmia. Success rates were 83% in patients without and 73% in patients with inducible arrhythmias at the end of the procedure (p=NS). CONCLUSION: CTI ablation, in addition to PV isolation, significantly reduced the number of patients with inducible atrial arrhythmias and inducible AF.

Travelers on beta-blockers: is malaria chemoprophylaxis dangerous?

Classic antimalarial drugs, particularly quinine and its derivatives, are well known for their potential pro-arrhythmic effects. Recently developed synthetic antimalarials are widely used among travelers for prophylaxis. Nevertheless, their safety is open to question, especially for travelers under common cardiovascular drug therapy. We report the case of a patient admitted for symptomatic high-grade atrioventricular (AV) block, caused by combined therapy with a common malaria prophylactic drug--mefloquine--and a beta-blocker prescribed for a symptomatic arrhythmia. Withdrawal of the beta-blocker led to disappearance of the AV block despite continuation of the malaria prophylaxis. Mefloquine drug interactions are briefly described, particularly in terms of the caution needed in travelers already under beta-blocker therapy in whom antimalarial drug prophylaxis is recommended.

Utility of tissue characterization in apical hypertrophic cardiomyopathy diagnosis.

A 60-year-old male with previous hypertension, left ventricle hypertrophy, and coronary artery disease was referred for stress echocardiography because of exertional chest pain. The electrocardiogram revealed deep T-wave inversion in the anterolateral leads. Contrast echocardiography was notable for an apical filling defect consistent with the apical form of hypertrophic cardiomyopathy. Cardiac magnetic resonance demonstrated the 'ace of spades' left ventricle cavity, confirming the diagnosis. Single photon emission computed tomography showed increased apical left ventricle tracer uptake. Velocity vector imaging study depicted lower than normal absolute maximal longitudinal tissue velocities. The apical longitudinal strain was negative without base to apex gradient. There were normal longitudinal strain values in the basal and mid myocardial segments (Figure 1). Apical hypertrophic cardiomyopathy is a rare condition occasionally missed by conventional echocardiographic studies. Intravenous contrast enhancement might improve diagnosis accuracy. Newer Doppler-based techniques allowing tissue characterization may complement contrast echocardiography in its diagnosis.

Load-independent parameters of diastolic and systolic function by speckle tracking and tissue doppler in hemodialysis patients.

BACKGROUND: Assessment of diastolic function using conventional Doppler techniques is limited by their significant dependence on volume load status. Whether new echocardiographic methods are load-independent in evaluating left ventricular systolic and diastolic function remains controversial. OBJECTIVE: The aim of this study was to identify load-independent echocardiographic parameters for systolic and diastolic function in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD) and to evaluate agreement between the new methods. METHODS: We studied 20 clinically stable patients with ESRD on HD for >4 months (mean age 51+/-12 years, 14 men, four with coronary disease). All had a transthoracic echocardiogram immediately before and after HD. Cardiac chamber volumes, left ventricular ejection fraction, and transmitral Doppler flow (E/A ratio) were determined according to American Society of Echocardiography guidelines. Pulsed tissue Doppler imaging (TDI) was used to record septal and lateral mitral annular velocities. Longitudinal systolic (Sm), early diastolic (Em) and late diastolic (Am) myocardial velocities and strain were determined by color TDI and also by speckle tracking imaging (STI), using apical views. The ratio between the rapid filling wave E and mitral early diastolic filling velocity (E/Em) and the Am/Em ratio were calculated, using spectral Doppler, pulsed TDI, color TDI, and STI. RESULTS: Mean ultrafiltration volume was 2800+/-820 ml (range 1200-4200 ml). Left atrial (LA) and left ventricular (LV) end-diastolic volumes and transmitral pulsed Doppler flow decreased significantly after HD. Early diastolic myocardial velocities also decreased significantly, regardless of the evaluation method. Filling pressure ratios were high and remained unchanged after HD. LV ejection fraction was >44% in all patients and did not change after HD. Systolic myocardial velocities, by any method, and global and longitudinal strain were also similar before and after HD. CONCLUSION: Large acute changes in volume load were associated with significant variations in early diastolic myocardial longitudinal velocities, thus demonstrating the dependence of Em on volume load. By contrast, E/Em ratios appeared to be load-independent, as were systolic function parameters. Pulsed TDI, color TDI, and STI yielded similar results for the assessment of diastolic and systolic myocardial parameters.

Peripheral artery disease: a cause of refractory hypertension after renal transplantation.

The authors report the case of a 44-year-old man, with a history of hypertension, smoking, peripheral artery disease and chronic renal failure. After renal transplantation, the patient developed persistent high blood pressure, despite optimal medical therapy. When angiotensin-converting enzyme (ACE) inhibitor therapy was begun, he developed acute anuric renal failure, which was reversed after interruption of the ACE inhibitor. After the initial clinical evaluation, the patient was referred for renal angiography, which revealed critical stenosis of the proximal left common iliac artery, just above the renal graft artery anastomosis. The patient underwent successful angioplasty and stenting of the lesion, with complete normalization of blood pressure.

Glucose metabolism in non-diabetic patients with stable coronary artery disease.

BACKGROUND: Diabetes and other forms of impaired glucose metabolism (IGM) can be present in patients with coronary artery disease (CAD), despite normal fasting glycemia and no prior evidence of diabetes. Undiagnosed IGM can be associated with increased risk of cardiovascular events. OBJECTIVE: To assess the prevalence of IGM in patients with CAD and without diabetes and to identify its repercussions on their cardiovascular risk profile. METHODS: Consecutive patients with CAD documented by angiography, without prior history of diabetes and fasting glycemia < 126 mg/dL, were studied. An oral glucose tolerance test (OGTT) was performed to identify and classify IGM. The patients were divided into three groups: normal if fasting glycemia < 100 mg/dL and normal OGTT; prediabetes if fasting glycemia > or = 100 mg/dL and abnormal OGTT, with 2-h glycemia > or = 140 and < 200 mg/dL; and diabetes if 2-h glycemia > or = 200 mg/dL after OGTT. For assessment of the cardiovascular risk profile, various clinical, laboratorial (including lipid profile, fasting insulinemia 2 h after OGTT, insulin resistance index and A1c hemoglobin) and angiographic characteristics were analyzed. The differences between groups were determined. RESULTS: 54 patients were studied (mean age 65 +/- 9 years, 78 % male) and IGM was identified in 37 (69%), with prediabetes in 23 (43%) and diabetes in 14 (26%). Patients with IGM had more dyslipidemia, higher levels of fasting glycemia, triglycerides and urea and lower HDL cholesterol. Metabolic syndrome was diagnosed in 12% of patients in the normal group, 44% in the prediabetes group and 50% in the diabetes group (p = 0.047). CAD was more severe in the presence of IGM, being multivessel in 84% of these patients versus 59% in the normal group (p = 0.046). CONCLUSION: In patients with CAD without clinical suspicion of diabetes, a routine OGTT can identify a significant percentage with prediabetes and diabetes, which can have a negative impact on their cardiovascular risk profile.