Pedro E. Horta

Mechanism of adenosine-induced elevation of pulmonary capillary wedge pressure in humans

BACKGROUND Continuous intravenous administration of adenosine to humans often results in a paradoxical rise in pulmonary capillary wedge pressure (PCWP), whereas arterial resistance is lowered and cardiac output and heart rate increase. This is believed to be due to diastolic stiffening of the ventricle or to a negative inotropic effect. In the present study, we tested these and other mechanisms by using pressure-volume (PV) analysis and echocardiography. METHODS AND RESULTS Fifteen patients with normal rest left ventricular function underwent cardiac catheterization and received adenosine at a rate of 140 micrograms/kg per minute IV for 6 to 10 minutes. PV relations were measured in 9 patients (without coronary artery disease) using the conductance catheter method. In 6 additional patients with coronary artery disease, echocardiograms were used to assess wall thickness and function, and aortic and coronary sinus blood, lactate, oxygen, and adenosine levels were measured. Adenosine increased PCWP by 19% (+2.6 mm Hg) in both patient groups while lowering arterial load by 30% and increasing cardiac output by 45% (all P < .001). There was no significant effect of adenosine on mean linear chamber compliance or monoexponential elastic stiffness, as the diastolic PV relation was unchanged in most patients. Diastolic wall thickness also was unaltered. Thus, the PCWP rise did not appear to be due to diastolic stiffening. Adenosine induced a rightward shift of the end-systolic PV relation (ESPVR) (+12.7 +/- 3.7 mL) without a slope change. This shift likely reflected effects of afterload reduction, as other indexes (stroke work-end-diastolic volume relation and dP/dtmax at matched preload) were either unchanged or increased. Furthermore, this modest shift in ESPVR was more than compensated for by vasodilation and tachycardia, so reduced systolic function could not explain the increase in PCWP. There also was no net lactate production to suggest ischemia. Rather than arising from direct myocardial effects, PCWP elevation was most easily explained by a change in vascular loading, as both left ventricular end-diastolic volume and right atrial pressure increased (P < .05). This suggests that adenosine induced a redistribution of blood volume toward the central thorax. CONCLUSIONS PCWP elevation in response to adenosine primarily results from changes in vascular loading rather than from direct effects on cardiac diastolic or systolic function.

Plasma lipid profile and coronary artery disease in Brazilian hemodialysis patients

We studied the prevalence of lipid disorders and of coronary artery disease and the main factors affecting plasma lipids in a cohort of Brazilian hemodialysis patients. The investigation comprised 75 adult hemodialysis patients and 200 normal controls matched for age, sex, race and body mass index. Mean values for plasma lipids were within normal limits in the dialysis group. Total cholesterol (184 +/- 44 vs. 201 +/- 46 mg/dl), LDL (110 +/- 36 vs. 131 +/- 44 mg/dl) and HDL (40 +/- 13 vs. 47 +/- 12 mg/dl) were significantly lower in the dialysis patients (P < 0.01), whereas VLDL (32 +/- 14 vs. 21 +/- 12 mg/dl) and triglyceride (161 +/- 71 vs. 111 +/- 70 mg/dl) were increased (P < 0.01). Increased triglyceride was observed in 24% of the dialysis patients, a prevalence two to three times lower than that reported in the literature. In the dialysis group, the variables positively related to total cholesterol were hypertension (P < 0.05) and gender (female) (P < 0.05); to LDL and HDL, hypertension (P < 0.05 and P < 0.01, respectively); and to triglyceride, use of propranolol (P < 0.01). Age, race, duration of hemodialysis, body mass index and plasma creatinine did not affect plasma lipids. The prevalence of coronary artery disease, established by invasive and noninvasive methods, was 10.7% while in the literature 20-35% of the unselected hemodialysis patients present obstructive coronariopathy. We conclude that the plasma lipid profile of Brazilian hemodialysis patients is similar to those reported in American and European literature, whereas the prevalence of hypertriglyceridemia and of coronary artery disease appears to be reduced.

Marcadores inflamatórios intracoronarianos após intervenções coronarianas percutâneas

OBJECTIVE To analyze intracoronary release of inflammatory markers (IM) after percutaneous coronary interventions (PCI) and compare their concentrations concerning the type of PCI used (rotablator vs. balloon angioplasty). METHODS Twenty-two patients with average age of 60 +/- 11.9 years old, 12 of male sex, with stable coronary disease, submitted to elective treatment of a single coronary lesion, using rotablator (N = 11) or balloon pre-dilatation (N = 11) for stent implant were randomized. Samples were collected at aorta root and coronary sinus, immediately before and 15 minutes after intervention. All dosages were made before stent implant, and the cytokines TNF-a, IL-6 and IL-1 and the soluble adhesion molecules ICAM-1, E-selectin and P-selectin were analyzed by using ELISA method. RESULTS TNF-a and IL-6 concentrations increased after PCI, respectively from 9.5 +/- 1.5 pg/ml to 9.9 +/- 1.8 pg/ml (p = 0.017) and from 6.0 +/- 2.4 pg/ml to 6.9 +/- 3.0 pg/ml (p < 0.001). There was no significant changes in IL-1, ICAM-1 and P-selectin, and a decrease in E-selectin concentrations after the procedures (52.0 +/- 17.5 ng/ml to 49.3 +/- 18.7 ng/ml; p = 0.009) was observed. There were no significant differences between IM concentrations after PCI, concerning the type of procedure used. CONCLUSION At the early period, post-percutaneous coronary interventions, an increase of intracoronary concentrations of TNF-a and IL-6, and absence of significant difference between concentrations of inflammatory markers released in coronary flow through rotablator and balloon angioplasty were observed.

Dissecção Espontânea de Artéria Coronária: Abordagem Terapêutica e Desfechos de Uma Série Consecutiva de Casos

Background: Spontaneous coronary artery dissection is a rare cause of acute coronary syndrome and diagnosis is made by necropsy in more than 70% of the cases. Optimal treatment is still uncertain, and the treatment options are percutaneous coronary intervention, coronary artery bypass surgery and medical therapy. The objective of this study was to evaluate the clinical characteristics, treatment modalities and outcome of a series of cases with spontaneous coronary artery dissection. Methods: Retrospective, single-center study, based on the analysis of the database at a high-complexity cardiology service. Results: We identified 25 patients with spontaneous coronary artery dissection, 56% were female, with a mean age of 48.8 ± 10 years. Only 24% had no risk factor for atherosclerosis and in 92% of the cases, the clinical presentation was of acute coronary syndrome. The left anterior descending artery was the most commonly affected vessel (48,1%) and there was only one case involving multiple vessels. The conservative approach was used in 56%, percutaneous coronary intervention in 40% and coronary artery bypass grafting in 4%. The in-hospital and late event-free survival was 92% and 84.2%, respectively. Conclusions: Spontaneous coronary artery dissection predominated in young women, with at least one risk factor for coronary artery disease. The choice of different therapeutic strategies confirms the still controversial nature of the optimal approach for spontaneous coronary artery dissection. We believe that individualized therapy is still the optimal modality.

Caracterização e impacto clínico tardio do no-reflow associado a intervenção coronária percutânea primária vs. eletiva

INTRODUCAO: Apesar dos grandes avancos alcancados pela cardiologia intervencionista, o fenomeno do no-reflow ainda ocorre durante as intervencoes coronarias percutâneas (ICP) e esta associado a pior prognostico. O objetivo deste estudo foi caracterizar os perfis clinico, angiografico e do procedimento de pacientes com no-reflow, alem de avaliar seu impacto clinico tardio. METODOS: Analisamos, no periodo de janeiro de 2004 a fevereiro de 2009, todos os pacientes submetidos a ICP no Instituto do Coracao (InCor), que em qualquer momento da intervencao apresentaram no-reflow, mesmo que transitoriamente. Os pacientes foram divididos em dois grupos: no-reflow de reperfusao (associado a ICP primaria) e no-reflow de intervencao (associado a ICP eletiva). A probabilidade de obito foi estimada pelo metodo de Kaplan-Meier e a regressao de Cox foi utilizada para identificar seus preditores. RESULTADOS: Foram avaliados 132 pacientes consecutivos, 81 no grupo no-reflow de reperfusao e 51 no grupo no-reflow de intervencao. O sucesso do procedimento foi obtido em 83,5% da populacao total (80,2% vs. 90,2%, respectivamente; P = 0,149). A probabilidade de mortalidade tardia foi estimada em 38,6%, sendo maior no grupo de no-reflow de reperfusao (55,8% vs. 11,1%; P = 0,005). Na analise multivariada, somente o sexo feminino [hazard ratio (HR) 2,5, intervalo de confianca de 95% (IC 95%) 1,22-5,14; P = 0,027) e a doenca pulmonar obstrutiva cronica (HR 9,3, IC 95% 1,45-60,14; P = 0,027) foram preditores independentes de mortalidade, enquanto o uso previo de estatina foi um fator de protecao (HR 0,15, IC 95% 0,05-0,48; P = 0,002). CONCLUSOES: O fenomeno de no-reflow foi associado a elevados indices de insucesso do procedimento e mortalidade tardia, principalmente quando associado a angioplastia primaria.

Desfechos tardios da intervenção coronária percutânea com stent farmacológico em pontes de veia safena: dados do registro InCor

BACKGROUND: The safety and efficacy of drug-eluting stents in the treatment of saphenous vein graft (SVG) lesions remains controversial. This study assessed the late follow-up of patients with SVG lesions treated with drug-eluting stents. METHODS: Single center registry including patients undergoing SVG interventions using drug-eluting stents (n = 82), without clinical or angiographic exclusion criteria, from 2003 to 2009. The rates of major adverse cardiac events (MACE), death, acute myocardial infarction (AMI), target vessel revascularization (TVR) and stent thrombosis were evaluated. RESULTS: Mean age was 67.8 ± 10.2 years, most of them were male (85.4%), 40.2% were diabetic and 52.4% had stable angina. An average of 1.45 ± 0.5 stents per patient were implanted and CypherTM was the stent used in most of the cases (61%). Stent diameter was 3.22 ± 0.39 mm and stent length was 20.1 ± 7.3 mm. Angiographic success rate was 96.3%. In the 4.1-year follow-up, the rate of MACE was 28%, death 6%, AMI 19.5% and TVR 18.2%. There were two cases of definitive or probable stent thrombosis (2.4%) within the follow-up period. CONCLUSIONS: Long-term follow-up showed high MACE rates in patients with SVG lesions treated with drug-eluting stents, probably due to the accelerated atherosclerosis that develops within the grafted vein conduits.

Stents convencionais de aço inoxidável vs. cromo-cobalto: impacto clínico da liga metálica no cenário atual - registro InCor

ABSTRACT Stainless Steel versus Cobalt-ChromiumBare Metal Stents: Clinical Impact of theMetal Alloy in a “Real World” Scenario –InCor Registry Background: Years ago studies demonstrated that the use ofcobalt-chromium stents with thinner struts significantly reducedcoronary restenosis when compared to conventional stainlesssteel stents available at the time. Since then, stents with struts< 100 µm and different metal alloys are available for clinicaluse. The objective of this study was to assess differences inthe clinical outcomes of patients undergoing percutaneouscoronary intervention (PCI) with thin strut stents and differentmetal alloys. Methods: Single center registry comparing theresults of patients undergoing PCI with stainless steel stents(n = 135) vs. cobalt-chromium bare metal stents (n = 181).The primary endpoint was the occurrence of major adversecardiac events (MACE), defined by death, acute myocardialinfarction (AMI) or target vessel revascularization (TVR) in thelate follow-up.

Perfil de segurança dos stents farmacológicos nas síndromes coronárias agudas: dados do Registro INCOR

BACKGROUND: Drug-eluting stents are a great advance in the treatment of coronary disease. However, their use in patients with acute coronary syndromes has been the subject of intense scientific debate. METHODS: 910 consecutive patients treated with at least one drug-eluting stent between May 2002 and September 2006 were enrolled in the present analysis. The patients were assigned to 2 groups according to their clinical condition at the time of admission: 1) Stable group (635 patients with stable angina) and 2) Acute group (275 patients with NSTEMI). We analyzed the clinical and angiographic characteristics as well as the occurrence of late adverse events. RESULTS: The clinical characteristics of the groups were similar, except for the highest incidence of smokers in the acute group and previous percutaneous intervention in the stable group. After 588 days (median follow-up period), the stable and acute groups had similar rates of re-infarction (2.8 vs. 5.0%; p = 0.1), target vessel revascularization (6.0 vs. 7.7%; p = 0.4), death (4.5 vs. 6.5%; p = 0.2) and composite major adverse cardiac events (9.9 vs. 11.9%; p = 0.4), respectively. However, the occurrence of in-stent thrombosis was more frequent in patients with acute coronary diseases (1.4 vs. 4.4%; p = 0.02), mainly due to the occurrence of thrombosis within the first year after implantation (1.1 vs. 4.4%; p = 0.01). CONCLUSION: Drug-eluting stents have shown a good safety profile in patients with acute coronary syndromes compared to those with chronic coronary disease, despite the higher incidence of late in-stent thrombosis.

Direct communication between the left circumflex and the right coronary arteries: a very rare coronary anomaly circulation.

Coronary artery anomalies (CAA) are congenital changes in their origin, course, and/or structure. Intercoronary communication (ICC) is a very rare subset with uni- or bidirectional blood flow between two or more coronary arteries. We present the case of a 58-year-old man with an acute coronary syndrome whose coronary angiography incidentally showed a surprising and very rare communication between the right coronary and left circumflex arteries.

Early Removal of the Arterial Sheath After Percutaneous Coronary Intervention Using the Femoral Approach: Safety and Efficacy Study

ABSTRACT Introduction We evaluated the safety and efficacy of protamine administration, guided by activated clotting time, for the immediate femoral arterial sheath removal in patients undergoing percutaneous coronary intervention with unfractionated heparin in order to propose an algorithm for clinical practice. Methods Prospective study with consecutive patients with stable angina or low-to-moderate risk acute coronary syndrome. We compared patients with an early removal of the arterial sheath to those whose sheath removal was based on a standard protocol. Results The early removal group (n = 149) had lower access manipulation time than the conventional group (58.3 ± 21.4 minutes vs. 355.0 ± 62.9 minutes; p p p = 0.49). There was no stent thrombosis during hospitalization and no significant differences in the incidence of major vascular or bleeding events. The incidence of other bleeding events leading to a prolonged in-hospital length of stay was lower in the early removal group (1.3% vs. 5.1%; p = 0.05). Conclusions: The selective use of an approach for immediate femoral sheath removal, based on activated clotting time guidance and protamine administration, is a safe and effective option in patients undergoing percutaneous coronary intervention by femoral access.