Electrocardiographic determination of culprit lesion site in patients with acute coronary events.

PURPOSE: The purpose of our study was to determine the ability of electrocardiographic (ECG) criteria derived from prior angiographic-ECG correlative studies to identify life-threatening coronary artery obstructive lesions. METHODS: We studied 128 consecutive patients referred from the emergency department for emergent coronary angiography for symptoms and ECG changes suggesting an acute coronary event. Using ECG criteria derived from prior studies, we attempted to predict not only the vessel housing the culprit lesion, but whether the lesion was located proximally in that vessel, and then determined the positive and negative predictive values (PPV and NPV) of the criteria used. RESULTS: Our criteria correctly identified 7 of 11 patients with left main disease, with a PPV of 100% and an NPV of 97%; 12 of 19 patients with proximal left anterior descending coronary artery disease, with a PPV of 67% and an NPV of 94%; and 25 of 28 patients with proximal right coronary artery disease, with a PPV of 64% and an NPV of 97%. The combined PPV and NPV for predicting patients with either left main coronary artery, proximal left anterior descending coronary artery, or proximal right coronary artery disease were 72% and 81%. CONCLUSION: Our study indicates that the location of life-threatening coronary artery lesions in patients presenting with signs and symptoms of acute coronary syndromes can be predicted from the initial ECG with a high degree of accuracy. Recognizing the ECG criteria for such lesions has the potential for shortening door-to-reperfusion time and improving patient outcomes.

The contrast media iohexol causes vasoconstriction of the proximal left anterior descending coronary artery: implications for appropriate stent sizing.

The effect of the contrast agent iohexol on reference vessel size in patients with proximal left anterior descending disease is unknown. Quantitative coronary angiography and intravascular ultrasound were performed in 15 patients with atherosclerotic disease of the proximal left anterior descending. Mean proximal reference vessel diameter was 2.95 +/- 0.59 mm with quantitative coronary angiography and 4.65 +/- 0.66 mm with intravascular ultrasound (P < .05). Intracoronary injection of iohexol resulted in a significant decrease in intravascular ultrasound-measured proximal reference vessel diameter from 4.65 +/- 0.66 mm to 4.47 +/- 0.68 mm (P = .002). Vasoconstrictive response to iohexol in the proximal reference vessel ranged from -0.04 mm to 0.5 mm with a mean of 0.18 +/- 0.16 mm. This study shows that iohexol can cause significant vasoconstriction of the proximal reference vessel in patients with severe disease involving the proximal left anterior descending.

Implementation of a statewide system for coronary reperfusion for ST-segment elevation myocardial infarction.

CONTEXT: Despite 2 decades of evidence demonstrating benefits from prompt coronary reperfusion, registries continue to show that many patients with ST-segment elevation myocardial infarction (STEMI) are treated too slowly or not at all. OBJECTIVE: To establish a statewide system for reperfusion, as exists for trauma care, to overcome systematic barriers. DESIGN AND SETTING: A quality improvement study that examined the change in speed and rate of coronary reperfusion after system implementation in 5 regions in North Carolina involving 65 hospitals and associated emergency medical systems (10 percutaneous coronary intervention [PCI] hospitals and 55 non-PCI hospitals). PATIENTS: A total of 1164 patients with STEMI (579 preintervention and 585 postintervention) eligible for reperfusion were treated at PCI hospitals (median age 61 years, 31% women, 4% Killip class III or IV). A total of 925 patients with STEMI (518 preintervention and 407 postintervention) were treated at non-PCI hospitals (median age 62 years, 32% women, 4% Killip class III or IV). INTERVENTIONS: Early diagnosis and the most expedient coronary reperfusion method at each point of care: emergency medical systems, emergency department, catheterization laboratory, and transfer. Within 5 regions, PCI hospitals agreed to provide single-call catheterization laboratory activation by emergency medical personnel, accept patients regardless of bed availability, and improve STEMI care for the entire region regardless of hospital affiliation. MAIN OUTCOME MEASURES: Reperfusion times and rates 3 months before (July to September 2005) and 3 months after (January to March 2007) a year-long implementation. RESULTS: Median reperfusion times significantly improved according to first door-to-device (presenting to PCI hospital 85 to 74 minutes, P < .001; transferred to PCI hospital 165 to 128 minutes, P < .001), door-to-needle in non-PCI hospitals (35 to 29 minutes, P = .002), and door-in to door-out for patients transferred from non-PCI hospitals (120 to 71 minutes, P < .001). Nonreperfusion rates were unchanged (15%) in non-PCI hospitals and decreased from 23% to 11% in the PCI hospitals. For patients presenting to or transferred to PCI hospitals, clinical outcomes including death, cardiac arrest, and cardiogenic shock did not significantly change following the intervention. CONCLUSIONS: A statewide program focused on regional systems for reperfusion for STEMI can significantly improve quality of care. Further research is needed to ensure that programs that result in improved application of reperfusion treatments will lead to reductions in mortality and morbidity from STEMI.

Mechanical thrombectomy options in complex percutaneous coronary interventions.

Percutaneous coronary interventions (PCI) of thrombus-containing lesions are associated with an increased risk of acute complications and poorer long term vessel patency. Dealing with these vessels provides many technical challenges, especially with the significant risk of coronary no reflow and distal embolization. Pharmacological strategies, including intravenous and intracoronary glycoprotein IIbIIIa inhibitors reduce intracoronary thrombus propagation, improve TIMI flow and are associated with a reduction in adverse event rates. Mechanical strategies (particularly embolic protection and thrombectomy catheters) help to improve coronary blood flow and myocardial perfusion. However, their impact on clinical outcomes is less clear. The use of embolic protection devices is associated with better perfusion, blood flow, and clinical outcomes among patients undergoing saphenous vein graft (SVG) PCI. However, the role for these devices in primary PCI and native coronary artery interventions is uncertain. This study examines the current approaches to manage thrombotic lesions during PCI and reviews the evidence in support of the different mechanical thrombectomy options that are available to the interventional cardiologist.

Comparison of bare metal stents versus drug-eluting stents on clinical decision making in patients with previous percutaneous coronary intervention admitted for suspected acute coronary syndrome.

To determine whether the decreased rate of restenosis observed with drug-eluting stents (DES) has changed the treatment of patients with recurrent symptoms after stent placement, we compared patients hospitalized with presumed cardiac symptoms within 1 year after placement of either a DES or a bare metal stent (BMS). In this retrospective, single-center study, cases were identified from consecutive patients who received a DES from March 2003 to July 2004 or a BMS from August 2001 to June 2002. No differences were noted in the rate of hospitalization, hospitalization for presumed cardiac symptoms, use of coronary angiography in patients hospitalized for presumed cardiac symptoms, or average interval to hospitalization. In contrast, restenosis and the need for additional revascularization procedures were higher in the BMS group. The primary indication for additional revascularization was restenosis in the BMS group and progression of coronary artery disease in the DES group. In the DES group, the need for revascularization was significantly higher in patients with multi- versus single-vessel coronary artery disease (26% vs 7%, p < 0.05). In conclusion, the rate of hospitalization and use of coronary angiography in patients with recurrent symptoms were similar in patients who received a BMS or DES, despite the decreased rates of restenosis and additional revascularization procedures observed with DESs.

The influence of body mass index on outcomes and the benefit of antiplatelet therapy following percutaneous coronary intervention.

UNLABELLED: In general, obesity is associated with better outcome in patients undergoing percutaneous coronary interventions (PCI). One small study has suggested that these patients do not achieve adequate platelet inhibition with clopidogrel and that this may shape clinical outcomes. We evaluated the relationship between body mass index (BMI) and clinical outcomes at 1 year following PCI in patients randomized to clopidogrel or placebo in the CREDO trial. METHODS AND RESULTS: BMI, baseline clinical characteristics and clopidogrel regimen were assessed in 2,116 patients. The primary study endpoint was the 1-year composite of death, MI or stroke. A total of 342 patients had low or normal BMI (< 25 kg per m2), 847 were overweight (25-29.9 kg per m2), 810 were obese (30-39.9 kg per m2) and 113 were very obese (greater than or equal to 40 kg per m2). Obese patients were more likely to be young males with diabetes, hypertension and hyperlipidemia (p < 0.01). Bleeding complications occurred in 38% of low BMI, 32% of overweight/obese, and 25% of very obese patients (p = 0.03). Randomization to clopidogrel was associated with a 25% risk reduction in 1-year death, MI or stroke events, as BMI increased by every 5 kg per m2 (p = 0.009). CONCLUSION: In general, increasing BMI was associated with better efficacy and bleeding outcomes at 1 year in this nonurgent PCI population. Randomization to early- and long-term clopidogrel was associated with even further improvements in those with increasing BMI.

Prevalence of symptomatic diastolic heart failure in patients hospitalized with cerebral or peripheral vascular disease.

The authors sought to determine the prevalence of diastolic heart failure (DHF) in patients hospitalized with their first stroke, transient ischemic attack, or new onset of peripheral vascular disease. A total of 216 prospective consecutive stroke, transient ischemic attack, and peripheral vascular disease patients (vascular group) were identified at their first noncardiac presentation to a hospital and compared with 164 age-matched control patients (nonvascular group). DHF was clinically defined as the presence of left ventricular ejection fraction>or=45% on echocardiography. DHF occurred in 40% and 73% of vascular and control patients, respectively, with symptomatic heart failure. Overall, it was found in 12% of vascular (10% of stroke/transient ischemic attack, 16% of peripheral vascular disease) and 11% of control patients. Advancing age and female gender were independently associated with the presence of DHF in vascular patients (p<0.05). DHF is found in a similar percentage of vascular and nonvascular patients. Symptomatic DHF is less common than systolic heart failure among vascular disease patients with heart failure. In contrast, symptomatic DHF is found in three times as many age-matched control heart failure patients without clinical vascular disease.

Safety of adjunctive intracoronary thrombolytic therapy during complex percutaneous coronary intervention: initial experience with intracoronary tenecteplase.

Intracoronary thrombus is associated with increased risk of in-laboratory vessel closure, recurrent myocardial infarction (MI), urgent vessel revascularization, and death. There is a lack of consensus on what represents the ideal treatment for patients with thrombotic complications during percutaneous coronary intervention (PCI), but the development of newer thrombolytic agents with increased fibrin specificity and longer half-life provides a potentially useful treatment option. In this study, the safety and efficacy of intracoronary tenecteplase (TNK) was evaluated in 34 patients (22 with acute ST elevation MI, 4 with rescue PCI, 6 with non-ST elevation MI, and 2 during elective PCI) who developed no-reflow, distal embolization, or visible intracoronary thrombus during PCI. The mean age was 57 years, 76% were Caucasian, and there were 14 women and 20 men. Cardiogenic shock was present in seven (21%) patients at baseline. All patients were being treated with aspirin and either unfractionated heparin (33 patients) or bivalrudin. Glycoprotein IIb/IIIa inhibitors were used in 76% of patients. Intracoronary TNK was used at a mean dose of 10.2 +/- 5.2 mg (median, 10 mg; range, 5-25 mg). There was one TIMI major bleeding event and three TIMI minor bleeding events. The mean hematocrit measured the morning following PCI was 35.5% +/- 4.9% in patients receiving TNK and 36.5% +/- 4.4% in a randomly selected sample of 150 consecutive patients undergoing PCI (P = 0.25). In conjunction with mechanical intervention, TNK was successful at dissolving angiographic thrombus and/or improving flow in 91% of patients. In conclusion, intracoronary TNK is safe and well tolerated in patients who develop thrombotic complications during complex PCI.

Pulmonary artery catheterization in acute coronary syndromes: insights from the GUSTO IIb and GUSTO III trials.

PURPOSE: To correlate pulmonary artery catheterization (PAC) use and 30-day outcomes and to characterize the use of pulmonary artery catheters among patients with acute coronary syndromes (ACS). SUBJECTS AND METHODS: We retrospectively studied 26437 ACS patients from two large multicenter, international randomized clinical trials. Multivariable and causal inference analyses were applied to adjust for differences in baseline risk. RESULTS: PAC was performed in 735 patients (2.8%), with a median time to insertion of 24 hours. Patients undergoing PAC were older (median, 67 vs. 64 years), more often diabetic (25.7% vs.16.2%), and more likely to present with ST-segment elevation (81.6% vs. 70.2%) or Killip class III or IV (7.9% vs. 1.4%). US patients were 3.8 times more likely than non-US patients to undergo PAC. Patients managed with PAC also underwent more procedures, including percutaneous intervention (40.7% vs. 18.1%), coronary artery bypass grafting (12.5% vs. 7.7%), and endotracheal intubation (29.3% vs. 2.2%). Mortality at 30 days was substantially higher among patients with PAC for both unadjusted (odds ratio [OR] 8.7; 95% confidence interval [CI] 7.3-10.2) and adjusted analyses (OR 6.4; 95% CI 5.4-7.6) in all groups except in patients with cardiogenic shock (OR 0.99; 95% CI 0.80-1.23). CONCLUSIONS: PAC was associated with increased mortality, both before and after adjustment for baseline patient differences and subsequent events that may have led to PAC use, except in patients with cardiogenic shock. The definitive role of PAC in managing patients with ACS is still to be determined.

Prevalencia de disfunción sistólica en pacientes con enfermedades vasculares / Prevalence of systolic dysfunction in patients with vascular diseases

Left ventricular systolic dysfunction (LVSD) is both common and treatable. These patients ought to be identified. A cost effective way to detect LVSD patients who would normally be missed might be to screen patients who present to hospital with their first noncardiac vascular event i.e. their first stroke, their first transient ischemic attack (TIA) or new onset of peripheral vascular disease (PVD). A consecutive series of 255 stroke, TIA and PVD patients aged between 45 and 86 years were identified at their first noncardiac vascular presentation to hospital. Age and gender matched controls (202) were recruited from family practice. Each patient underwent a history, physical examination, echocardiography and a 12 lead ECG. LVSD was defined as LVEF ≤ 40%. LV dysfunction was found in 28% of vascular patients compared with 5.5% of age and gender-matched controls. Almost two thirds of LVSD patients were asymptomatic. LVSD is more common in stroke, TIA and PVD patients than in the general population. Our findings would suggest that there is enough LVSD in such patients to warrant routine screening.Future studies should consider whether screening for LVSD in these patients would reduce high rate of cardiac death.

La disfunción sistólica del ventrículo izquierdo (DSVI) es tan frecuente como tratable. Entonces, deberíamos identificar estos pacientes. Una manera rentable de detectar los enfermos con DSVI que habitualmente se pasarían por alto podría ser la pesquisa de los pacientes que se presentan en el hospital por un primer episodio vascular no cardíaco, por ejemplo, su primer accidente cerebro vascular (ACV), accidente isquémico transitorio (AIT) o un nuevo episodio de enfermedad vascular periférica (EVP). Pacientes pertenecientes a una serie consecutiva de 255 enfermos con ACV, AIT y EVP, de entre 45 y 86 años, fueron identificados en su primer ingreso en el hospital por patología vascular no cardíaca. Además, se convocaron 202 controles equiparables por edad y sexo provenientes del servicio de medicina familiar. A cada paciente se le realizó historia clínica, examen físico, ecocardiografía y a 12 se les efectuó ECG. La DSVI fue definida como una fracción de eyección del ventrículo izquierdo (FEVI) igual o menor del 40%. Se encontró disfunción del ventrículo izquierdo (VI) en 28% de los pacientes vasculares, en comparación con 5.5% de los controles equiparados por edad y sexo. Casi dos tercios de los pacientes con DSVI eran asintomáticos. La DSVI es más común en los pacientes con antecedentes de ACV, AIT y EVP que en la población general. Nuestros hallazgos sugieren que la incidencia de DSVI en este tipo de pacientes justifica efectuar una pesquisa de rutina. Futuros estudios deben considerar si la pesquisa de DSVI en estos pacientes podrá reducir el alto índice de fallecimiento por causas cardíacas.

Facilitated percutaneous coronary intervention in acute myocardial infarction: attractive concept but difficult to prove!

Facilitated percutaneous coronary intervention (PCI) refers to a strategy of immediate PCI following the administration of pharmacological therapies in acute myocardial infarction. It has evolved primarily from the time delays (due to geography or logistics) in getting acute myocardial infarction patients to the catheterization laboratory and the associated irreversible loss of myocardial muscle that occurs as door-to-balloon time increases. Facilitated PCI provides an opportunity to start treating many of these patients before they reach the catheterization laboratory and provides an ability to open the infarct-related artery before PCI, which is associated with better outcomes for AMI patients. Pharmacological strategies before PCI include: thrombolytic therapy, glycoprotein IIb/IIIa inhibitor alone, or a combination of thrombolytic therapy plus glycoprotein IIb/IIIa inhibitor. Initial results of angiographic studies show better patency with the latter strategy but at the expense of higher bleeding event rates. Ongoing trials are evaluating different combinations of thrombolytic and glycoprotein IIb/IIIa inhibitor therapy.