Early dysfunction and long-term improvement in endothelium-dependent vasodilation in the infarct-related artery after thrombolysis.

OBJECTIVES: This study assessed the degree of endothelial dysfunction in post-acute myocardial infarction (AMI) and its subsequent status in the infarct-related artery (IRA) in patients treated with thrombolysis. BACKGROUND: Coronary flow reserve alterations in the IRA after thrombolysis have been described, but the endothelium-dependent vasomotion has not been investigated, to date. METHODS: Endothelial function in patients after thrombolysis was assessed by infusion of acetylcholine (ACh) at increasing doses in the IRA. Diameter changes in the distal segments were evaluated using quantitative coronary angiography. Patients with coronary atherosclerosis constituted the control group. Clinical variables, electrocardiography and biochemical markers were used to determine the timing of reperfusion and the extent of the infarct. Patients in the AMI group were re-evaluated one year later. RESULTS: In the initial assessment, 16 patients showed a vasoconstriction response to ACh in the IRA compared to the control group (-20 +/- 21% vs. 4 +/- 4%; p < 0.01). Significant correlations between the degree of vasoconstriction and maximum value of the creatine kinase-MB fraction and number of new Q waves were observed. Of the 12 patients re-evaluated, 4 had complete occlusion of the IRA. In the remaining eight patients with patent artery, an improvement in response to ACh was observed relative to the initial study (+3 +/- 11%, vs. -19 +/- 15%, p < 0.05). CONCLUSIONS: In patients with AMI treated with thrombolysis, severe endothelial dysfunction in the IRA is observed early. In patients who retain patency of the IRA, the endothelial dysfunction improves during the follow-up and suggests a component of stunned endothelium in the first few days post-AMI.

Persistence of lung function abnormalities despite sustained success of percutaneous mitral valvotomy: the need for an early indication.

AIMS: We assessed early and long-term pulmonary function changes after percutaneous balloon mitral valvotomy (PBMV). METHODS AND RESULTS: Mitral area, lung function, and exercise capacity were evaluated before, immediately after, and 3 months, 6 months, and 12 months after successful PBMV in 24 patients. PBMV resulted in a significant and sustained increase in mitral area, from 1.0 +/- 0.1 to 1.9 +/- 0.1 cm2 (p = 0.001) [mean +/- SD], with a progressive increase in exercise tolerance at 6-month follow-up (from 22.6 +/- 1.4 to 28.2 +/- 1.2 mL/kg, p = 0.0001). An immediate drop in the diffusing capacity of the lung for carbon monoxide (DLCO) was observed (from 26.7 +/- 1.5 to 22.3 +/- 1.1 mL/min/mm Hg, p = 0.0002) after PBMV, followed by a gradual regression to baseline values at 3 months; at 1 year, the DLCO remained elevated (27.3 +/- 6.3 mL/min/mm Hg). The flow in the small airways was reduced at baseline, and there was no significant change during follow-up. CONCLUSIONS: PBMV produces an initial decrease in DLCO, suggesting a reduction of pulmonary congestion. During follow-up, the regression to the initial lung diffusion values despite a sustained hemodynamic improvement suggests that some irreversible interstitial changes were present. In patients with mitral stenosis, an impairment of lung function parameters suggests that PBMV must be performed early, even if patients have few symptoms.

[Drug-eluting stents in patients with left main coronary lesions who are not candidates for surgical revascularization]. / Stent liberador de fármacos en lesiones de tronco coronario izquierdo en pacientes no candidatos a revascularización quirúrgica.

INTRODUCTION AND OBJECTIVES: Surgical revascularization is the treatment of choice in patients with left main coronary artery stenosis. Conventional stents are not a valid alternative because of the rate of restenosis and sudden cardiac death. Drug-eluting stents, which reduce the rate of restenosis, may represent an alternative to cardiac surgery. The objective of this study was to describe the results with drug-eluting stents in patients with left main coronary artery stenosis who were poor candidates for surgical revascularization. PATIENTS AND METHOD: We prospectively followed a consecutive series of patients who were poor candidates for surgical revascularization and were treated with implantation of a drug-eluting stent in the left main coronary artery between May 2002 and April 2004. In-hospital and long-term results were analyzed. Follow-up included angiographic and intravascular ultrasound (IVUS) studies. RESULTS: Forty-two patients (25 men, 59.5%) with a mean age of 70.1 (10.5) years were studied. Fourteen (33%) had diabetes, and 7 (16.7%) had a protected left main coronary artery. The reasons for ruling out surgery were poor distal vessels in 19 (45.2%), previous surgery in 9 (21.4%), age in 6 (14.3%), primary angioplasty in 5 (11.4%), and other reasons in 3 (7.2%). Four patients (9.5%) died before discharge, three of them after primary angioplasty. No in-hospital revascularization procedures were needed. Median follow-up time was 288 days; mean follow-up time was 315 (241) days. Another four patients died after discharge (9.5%) on days 5, 24, 34 and 115. Angioplasty was repeated in one patient, and another was referred for heart transplantation. CONCLUSIONS: Drug-eluting stents represent a valid alternative in patients with left main coronary artery stenosis who are poor candidates for surgical revascularization. Randomized studies with a longer follow-up should be performed to evaluate their benefits in patients eligible for surgery.

[Elevated troponin I levels in patients with acute coronary syndrome without ST elevation are associated with increased complexity of the culprit lesion]. / Las elevaciones importantes de troponina I en el síndrome coronario aguso sin elecación del segmento ST se asocian a estenosis coronarias más complejas.

INTRODUCTION: The prognosis in patients with acute coronary syndrome without persistent ST segment elevation (NSTEACS) differs depending on cardiac troponin levels. Clinical practice guidelines published by the Spanish Society of Cardiology and the ACC/AHA consider patients with NSTEACS and markedly elevated troponin levels as high risk patients. The aim of this study was to identify factors related to markedly elevated troponin I levels in NSTEACS. PATIENTS AND METHOD: We measured troponin I levels in 219 consecutive patients with NSTEACS and normal CK-MB values, and identified 2 groups: patients with markedly elevated troponin levels (more than 10-fold the normal upper limit), and patients with normal or slightly elevated troponin levels (less than a 10-fold increase above the normal limit). We also analyzed clinical and angiographic variables. Logistic regression was used to calculate age- and sex-adjusted associations for the main variables. RESULTS: Forty-one patients (19%) had markedly elevated troponin levels, and 178 (81%) showed normal or slightly elevated troponin I levels. Patients with markedly elevated levels had more frequently prolonged angina, class IIb angina, more severe ECG changes, a higher number of diseased vessels on coronary angiography, and greater severity of the culprit lesion. The culprit stenosis in these patients was more often characterized as ulcerated, showing visible thrombus, and excentric, bifurcated and irregular. Class IIIb angina (odds ratio [OR] = 3.1; CI 95%, 1.1-8.6), bifurcation (OR=6.04; CI 95%, 2.5-14.3), ulceration (OR=3.2; CI 95%, 1.07-9.7) and visible thrombus (OR=2.7; CI 95%, 1.1-6.3) in the culprit lesion were predictive factors associated with markedly elevated levels of troponin I independently of age or sex. CONCLUSIONS: Markedly elevated troponin I levels in patients with NSTEACS are associated with a more severe clinical presentation and increased complexity of the culprit lesion on coronary angiography.

Minor myocardial damage during percutaneous coronary intervention does not affect long-term prognosis.

INTRODUCTION AND OBJECTIVES: To determine whether long-term prognosis is affected by myocardial damage taking place during percutaneous coronary intervention (PCI). METHODS: The study included consecutive patients undergoing PCI. Those with elevated baseline cardiac marker levels were excluded. Cardiac markers were evaluated and an ECG was recorded before and 12 and 24 hours after PCI. Patients were divided into three groups after PCI according to their cardiac marker levels: no myocardial damage (i.e. normal troponin and creatine kinase MB fraction [CK-MB]), minor damage (elevated troponin with normal CK-MB), and myonecrosis (elevated troponin and CK-MB). The occurrence of death, myocardial infarction or repeat revascularization during follow-up was recorded. RESULTS: Minor myocardial damage associated with PCI was observed in 127 (16.8%) of the 757 patients included in the study and myonecrosis, in 46 (6.1%). During a follow-up of 45+/-14 months, cardiac events occurred in 151 (19.1%) patients. Mortality during follow-up was significantly higher in patients with myonecrosis (13%) than in the other two groups (4.8% and 3.9%; log rank, 6.83; P=.032). No difference was observed in the rate of myocardial infarction or repeat revascularization during follow-up. CONCLUSIONS: Minor myocardial damage during PCI had no effect on long-term prognosis. In contrast, myonecrosis was associated with increased mortality. Consequently, the CK-MB level should be measured after all PCIs because of its prognostic implications, and strategies for reducing the risk of myonecrosis developing should be implemented.

Endothelial-dependent vasoconstriction in the infarct-related artery early after myocardial infarction is smaller following primary angioplasty than thrombolytic therapy.

INTRODUCTION AND OBJECTIVES: In patients with ST-elevation acute myocardial infarction treated by thrombolysis, both early endothelial dysfunction and long-term improvement in the infarct-related artery have been reported. Our aims were to assess the degree of endothelial dysfunction present after primary angioplasty and to compare it with that after thrombolysis. METHODS: Endothelial function was assessed 9 days after infarction by infusing acetylcholine, at an increasing concentration, and subsequently nitroglycerine into the infarct-related artery in 16 patients who had undergone primary angioplasty and bare-metal stent implantation. In addition, endothelial function was compared with that in a group of 16 patients treated by thrombolysis in a different time period. The mean change in the diameters of segments distal to the culprit lesion or the treated lesion were evaluated by quantitative coronary angiography. RESULTS: Baseline characteristics were similar in the two groups, except that patients in the primary angioplasty group were treated with clopidogrel and there were differences in residual stenosis in the infarct-related artery (3% in the primary angioplasty group compared with 62% in the thrombolysis group). At the maximum acetylcholine concentration, the degree of vasoconstriction was less in the primary angioplasty group than in the thrombolysis group (-4+/-5% vs. -20+/-21%; P=.018). CONCLUSIONS: Early endothelium-dependent vasoconstriction in the infarct-related artery was lower in acute myocardial infarction patients treated by primary angioplasty and bare-metal stent implantation than in those treated by thrombolysis.