Time Of Diagnostic Catheterization Research Articles

Abstract 10266: T-Wave Features Predict Functional Worsening in Children With Pulmonary Arterial Hypertension: Machine Learning Insights From Standard ECG

Introduction: Various T-wave characteristics have been shown to be predictive of ventricular diastolic dysfunction and sudden cardiac death in adults. However, specific T-wave morphologies and their predictive potential in pediatric patients is unknown. Hypothesis: Machine learning derived T-wave characteristics will be different between children with pulmonary arterial hypertension (PAH) and healthy controls. Furthermore, T-wave characteristics will be predictive of clinical functional worsening in PAH patients. Methods: Principal component analysis (PCA) was applied to ECGs collected for children with PAH (n=155) at the time of diagnostic catheterization and matched healthy controls (n=47) to describe basic T-wave characteristics. Patients (<18 y/o) with PAH were defined as a mean pulmonary pressure >25 mmHg in the absence of obstructive left heart disease. Interpreted T-wave features were then compared between PAH and control groups. Identified T-wave measurements underwent survival analysis using standardized PAH functional class worsening as a clinical endpoint. Results: Identified T-wave principal components were 1) T-wave height and 2) early or late incidence of T-wave peak (FIGURE- 1A). The second principal component was associated with PAH diagnostic specificity (94%). Time from T-wave peak to T-wave end (TpTe) as measured in leads V4 to V6 was significantly higher in children with PAH (all P < 0.001) (FIGURE - 1B). V4 derived TpTe value > 132 ms and V5 derived TpTe value > 135 ms were associated with the higher probability of clinical functional worsening (P = 0.018 and P = 0.002, respectively) (FIGURE - 1C). Conclusions: T-wave features derived from standard ECG are 1) different between children with PAH and their healthy peers and 2) predictive of clinical functional worsening.

Staging of multivessel percutaneous coronary interventions: An expert consensus statement from the Society for Cardiovascular Angiography and Interventions

Percutaneous coronary interventions (PCIs) to treat multivessel coronary artery disease (MVCAD) may involve single-vessel or multivessel interventions, performed in one or more stages. This consensus statement reviews factors that may influence choice of strategy and includes six recommendations to guide decisions regarding staging of PCI. Every patient who undergoes PCI should receive optimal therapy for coronary disease, ideally before starting the procedure. Multivessel PCI at the time of diagnostic catheterization should be considered only if informed consent included the risks and benefits of multivessel PCI and the risks and benefits of alternative treatments. When considering multivessel PCI, the interventionist should develop a strategy regarding which stenoses to treat or evaluate, and their order, method, and timing. This strategy should maximize patient benefits, minimize patient risk, and consider the factors described in this article. For planned multivessel PCI, additional vessel(s) should be treated only if the first vessel is treated successfully and if anticipated contrast and radiation doses and patient and operator conditions are favorable. After the first stage of the planned multistage PCI, the need for subsequent PCI should be reviewed before it is performed. Third party payers and quality auditors should recognize that multistage PCI for MVCAD is neither an indication of poor quality nor an attempt to increase reimbursement when performed according to recommendations in this article.

Risk of Major Complications From Coronary Angioplasty Performed Immediately After Diagnostic Coronary Angiography: Results From the Registry of the Society for Cardiac Angiography and Interventions

Objectives. This study was designed to determine the risk of performing percutaneous transluminal coronary angioplasty (PTCA) at the time of diagnostic catheterization (“combined procedures”).Background. Health care providers are under increasing pressure to combine diagnostic and interventional coronary procedures to reduce costs. However, the risk associated with combined procedures has not been rigorously assessed.Methods. A multicenter cohort study of 35,700 patients undergoing elective PTCA from 1992 through 1995 was performed to determine the risk of major complications (myocardial infarction, emergency coronary artery bypass graft surgery or death) from combined relative to staged procedures (i.e., performing PTCA at a session subsequent to diagnostic catheterization).Results. The risks of major complications from combined and staged procedures were 2.0% and 1.6%, respectively (unadjusted odds ratio [OR] 1.28, 95% confidence interval [CI] 1.05 to 1.57). After adjusting for clinical and angiographic differences and clustering by laboratory, the risk from combined procedures was not significantly elevated (multivariable OR 1.18, 95% CI 0.89 to 1.55). However, several subgroups of patients did have an increased risk from combined procedures: patients with multivessel disease (multivariable OR 1.64, 95% CI 1.13 to 2.39); women (multivariable OR 1.64, 95% CI 1.05 to 2.55); patients >65 years old (multivariable OR 1.40, 95% CI 1.02 to 1.93); and patients undergoing multilesion PTCA (multivariable OR 1.53, 95% CI 1.06 to 2.21). The risk of combined relative to staged procedures decreased over the 4-year period (multivariable p = 0.029).Conclusions. Combining PTCA with diagnostic catheterization appears to be safe in many patients. However, several subgroups of patients may be at increased risk. Careful patient selection will most likely remain critical to ensuring the safety of combined procedures.(J Am Coll Cardiol 1997;30:193–200)

Assessing the hemodynamic significance of coronary artery stenosis: Analysis of translesional pressure-flow velocity relations in patients

Objectives. The purpose of this study was to examine the relation among the angiographic severity of coronary artery lesions, coronary flow velocity and translesional pressure gradients.Background. Determination of the clinical and hemodynamic significance of coronary artery stenosis is often difficult and inexact. Angiography has been shown to be an imperfect tool for determining the physiologic significance of eccentric or irregular coronary lumen narrowing.Methods. Using a 0.018-in. (0.046 cm) intracoronary Dopplertipped angioplasty guide wire, spectral flow velocity data both proximal and distal to coronary stenoses were compared with translesional pressure gradient measurements and angiographic data obtained during cardiac catheterization in 101 patients. There were 17 patients with normal angiographic findings and 84 with coronary artery disease, with lesions ranging from 28% to 99% diameter narrowing. Patients with coronary disease were assigned to two groups on the basis of translesional gradients at rest. Group A (n = 56) had gradients <20 mm Hg, and Group B (n = 28) had gradients ≥20 mm Hg.Results. Proximal average peak velocity, diastolic velocity integral and total velocity integral were slightly but statistically lower in Group A; however, the distal average peak velocity and diastolic and total velocity integrals were all markedly (all p < 0.01) decreased in patients with gradients ≥20 mm Hg (Group B). In addition, the ratio of proximal to distal total flow velocity integral was higher in Group B (2.4 ± 1.0) than in group A (1.1 ± 03, p < 0.001). There was a strong correlation between translesional pressure gradients and the ratios of the proximal to distal total flow velocity integrals (r = 0.8, p < 0.001), with a weaker relation between quantitative angiography and pressure gradients (r = 0.6, p < 0.001). In angiographically intermediate stenoses (range 50% to 70%), angiography was a poor predictor of translesional gradients (r = 0.2, p = NS), whereas the flow velocity ratios continued to have a strong correlation (r = 0.8, p < 0.001). Only two patients with a proximal/distal total flow velocity ratio <1.7 had a translesional gradient >30 mm Hg. Both patients had a very proximal lesion in a nonbranching right coronary artery.Conclusions. These data demonstrate that in branching human coronary arteries, a close relation exists between translesional hemodynamics and distal coronary flow velocity. Translesional coronary flow velocity is a new and easily applicable method for determining the hemodynamic significance of coronary artery stenoses that is superior to angiography and can be applied at the time of diagnostic catheterization. These data will provide a rational approach to making decisions on the use of coronary interventional techniques when angiographic findings are questionable.

Assessment of angiographically intermediate coronary artery stenosis using the Doppler flowire

Determination of the clinical and hemodynamic significance of coronary stenoses is often difficult and inexact. Angiography and coronary vasodilator reserve have been shown to be imperfect tools to determine the physiologic significance of coronary stenoses. Spectral flow velocity data, both proximal and distal to coronary stenoses, using an 0.018-in intracoronary Doppler-tipped angioplasty guidewire, were compared to translesional pressure gradients and angiography during cardiac catheterization. Patients were divided into 2 groups based on resting translesional gradients: Group 1 had gradients <20 mm Hg and group 2 had gradients ≥20 mm Hg. Proximal average peak velocity, diastolic velocity integral, and total velocity integral were statistically significantly lower in Group 1. The distal average peak velocity, and diastolic and total velocity integrals were all significantly (p < 0.01) decreased in patients with gradients >20 mm Hg (group 2). The ratio of proximal-to-distal total flow velocity integral was also higher in group 2 patients (2.3 ± 0.9) compared with group 1 (1.1 ± 0.2; p < 0.001). There was a strong correlation between translesional pressure gradients and the ratios of the proximal-to-distal total flow velocity integrate (r = 0.8, p < 0.001) with a weaker relationship between quantitative angiography and pressure gradients (r = 0.6, p < 0.001). Angiography was a poor predictor of translesional gradients in angiographically intermediate stenoses (range 50–70%; r = 0.2, p = NS), white the flow velocity ratios continued to have a strong correlation (r = 0.8, p < 0.0001). Translesional coronary flow velocity te a new and easily applicable method for determining the hemodynamic significance of coronary stenoses that can be applied at the time of diagnostic catheterization. These data will provide a rational approach to decisions for questionable angiographic findings for coronary interventional techniques.

Management and immediate outcome of patients with intracoronary thrombus during percutaneous transluminal coronary angioplasty

A retrospective analysis of our experience with intraprocedural thrombus complicating percutaneous transluminal coronary angioplasty (PTCA) was undertaken. Of 983 PTCA procedures reviewed, 62 (6.3%) were complicated by thrombus. Patients were managed conservatively (group I, n = 18), with redilation (group II, n = 17), or with intracoronary urokinase and redilation (group III, n = 27). The three groups did not differ with respect to demographic or baseline angiographic variables, but complications, defined as death, myocardial infarction, bypass surgery, or threatened occlusion requiring emergency stenting, occurred in 11% of patients in group I, 24% in group II, and 48% in group III. Occlusive thrombus behavior was observed in 80% of these 62 patients. Patients with complications were less likely to have received antecedent antiplatelet therapy (79% vs 95% of patients without complications), had more complex baseline lesion morphology, more often had thrombus present at baseline (42% vs 19%), and more often had a low activated clotting time at the start of PTCA (53% vs 8%). Thrombi that led to complications more frequently exhibited occlusive behavior before therapy was begun (95% vs 71%) and more often occurred in the setting of intimal dissection (42% vs 14%). Patients undergoing PTCA at the time of diagnostic catheterization were more likely to have complications than those in whom PTCA was delayed. A successful outcome was more likely (83% vs 27%, p = 0.03) in group III if at least 140,000 U of urokinase were administered within 50 minutes of the appearance of thrombus. Thus intracoronary thrombus formation during PTCA remains a significant source of morbidity. Antecedent antiplatelet therapy and intensive anticoagulation at the start of PTCA are important in avoiding complications resulting from thrombus formation. Intracoronary infusion of urokinase when initiated promptly appeared to minimize the frequency of complications and improve the angiographic results.

Repeat coronary angioplasty during the sameangiographic diagnosis of coronary restenosis

To determine whether any differences exist in results of treatment of restenosis with repeat angioplasty when the procedure is performed during diagnosis or, as an alternative, when it is performed as a separate elective procedure, we prospectively compared the outcome of 48 consecutive procedures (including 51 lesions) at the time of initial cardiac catheterization (group 1) with the outcome of 26 consecutive elective procedures (including 30 lesions) (group 2). Before control angiography was performed, the anatomic and procedural characteristics of the previous dilatation and the new symptomatic status were carefully reevaluated in all patients. Baseline clinical and angiographic characteristics including age, sex, ejection fraction, and number of diseased vessels in which repair was attempted were similar in both groups. Reasons for angioplasty were also similar with unstable angina being the most frequent indication: 29 (60%) in group 1 versus 13 (50%) in group 2. (p = NS). Morphology of the lesions was also similar, although longer lesions (greater than 12 mm) were dilated in group 2 (13 (43%) vs 10 (20%) in group 1; p less than 0.05). Angiographic success was achieved in 51 lesions (100%) in group 1 versus 28 (93%) in group 2 (p = NS). Primary angioplasty success (in the absence of major complications) was achieved in 46 (95%) procedures in group 1 versus 24 (92%) in group 2 (p = NS). Two patients in group 1 had a myocardial infarction, but there were no other major complications in either group. Preliminary data suggest that the outcome of repeat coronary angioplasty for restenosis is similar whether it is performed at the time of diagnostic catheterization or later on as an independent elective procedure.

Safety and efficacy of percutaneous transluminal coronary angioplasty performed at time of diagnostic catheterization compared with that performed at other times

Performing diagnostic cardiac catheterization and percutaneous transluminal coronary angioplasty (PTCA) as a single, combined procedure might provide savings in patient hospitalization days and more efficient use of catheterization laboratory time. To assess the safety and efficacy of combined diagnostic coronary angiography and PTCA, we reviewed all elective PTCA procedures performed at our institution during 1985 and 1986 so that we could compare patients who had diagnostic angiography and angioplasty on separate days (n = 404) with those who had the combined procedure (n = 120). The success rate and incidences of urgent bypass surgery, acute myocardial infarction, transient azotemia and procedure-related death were not different in the 2 groups. The mean hospitalization time was 6.2 days in the group with combined angiography and angioplasty, and 7.3 days in the group having separate procedures.

Clinical, haemodynamic and angiographic predictors of survival in unoperated patients with aortic stenosis. The VA Cooperative Study on Valvular Heart Disease.

One hundred baseline characteristics obtained at the time of diagnostic catheterization were examined for their prognostic value in 106 patients with unoperated aortic stenosis entered into the VA Cooperative Study on Valvular Heart Disease. A stepwise series of univariate and multivariate survival analyses were used to identify the independently significant prognostic indicators. Measures of the severity of valve stenosis, presence of coronary artery disease, and congestive heart failure are the important indicators of survival in unoperated aortic stenosis.

Balloon dilatation of calcific aortic stenosis in elderly patients: postmortem, intraoperative, and percutaneous valvuloplasty studies.

To assess the safety and efficacy of percutaneous balloon valvuloplasty in calcific aortic stenosis, balloon dilatation of critically stenosed, calcified aortic valves was performed in five postmortem hearts, in five patients intraoperatively before aortic valve replacement, and in two elderly patients percutaneously at the time of diagnostic catheterization. The etiology of aortic stenosis in the 12 cases was rheumatic in two, congenital bicuspid calcific stenosis in one, and senile calcific degenerative stenosis in the remaining nine. Prevalvuloplasty examination in the 10 postmortem and intraoperative cases revealed rigid valve leaflets with commissural fusion in three valves and extensive nodular calcification in seven. Subsequent balloon dilatation with 15 to 18 mm valvuloplasty balloons resulted in decreased cusp rigidity and increased mobility of valve leaflets in all cases, without evidence of tearing of valve leaflets, disruption of the valvular ring, or liberation of calcific or valvular debris. In the three valve specimens with commissural fusion, balloon dilatation resulted in partial or complete separation of leaflets along fused commissures. In two cases with extensive nodular calcification, balloon dilatation resulted in a fracture of a calcified leaflet that was evident on both gross and radiologic examination. After postmortem and intraoperative studies, percutaneous catheter valvuloplasty was performed at the time of diagnostic catheterization in two elderly patients (93- and 85-year-old women) with long-standing calcific aortic stenosis. Balloon dilatation with 12 to 18 mm balloons resulted in significant decreases in aortic gradients and significant increases in cardiac index and aortic valve area in both patients. Percutaneous valvuloplasty in both patients resulted in a mild increase in aortic insufficiency and no evidence of embolic phenomena.

Correlates of prolonged HV conduction in aortic stenosis

Forty-eight patients with predominant aortic stenosis underwent His bundle electrography (HBE) at the time of diagnostic catheterization. Patients were divided into four groups based upon severity of calcification of the aortic valve fluoroscopically as judged independently by three angiographers. Of 48 patients, three had no calcification, 11 had mild, 18 had moderate, and 16 had severe aortic valve calcification. No correlation was found between HV interval and severity of aortic valve calcification. Significant correlation was found between HV interval prolongation and aortic valve area ( p < 0.02), history of congestive heart failure ( p < 0.02), and increasing left ventricular end-diastolic pressure ( p < 0.05). Left ventricular ejection fraction <45% had greater likelihood of HV interval prolongation ( p < 0.01). No correlation was established between HV interval and age, aortic valve gradient, left ventricular peak systolic pressure, syncope, and coronary artery disease. Aortic valve area was the most significant independent predictor of HV prolongation, with history of congestive heart failure second. We conclude that HV interval prolongation in aortic stenosis with calcified valves is best predicted by evidence of declining left ventricular function rather than severity of aortic valve calcification.

Usefulness of transstenotic coronary pressure gradient measurements during diagnostic catheterization

A difficult problem in coronary arteriography is the assessment of the hemodynamic significance of stenoses that appear angiographically to be of only moderate severity (25 to 75% diameter narrowing). This is particularly important in patients who may be candidates for invasive therapy, such as percutaneous transluminal coronary angioplasty (PTCA) or coronary bypass surgery. To determine the significance of such lesions, we measured transstenotic coronary pressure gradients in 15 patients with angiographically moderate stenoses. For comparison, similar measurements were made in 17 patients with severe stenoses (more than 75% diameter narrowing) being considered for PTCA. The transstenotic pressure gradients were measured with a 2.0Fr polyvinyl chloride catheter cleared of microbubbies of air by flushing with carbon dioxide and degassed saline solution and attached to a low-volume displacement transducer for optimal frequency response. Mean transstenotic pressure gradients greater than 10 mm Hg at rest or more than 20 mm Hg under conditions of high coronary blood flow, as induced by Renografin 76, appeared to be associated with objective evidence of myocardial ischemia and symptomatic relief from PTCA. Smaller pressure gradients occurred in patients whose symptoms probably were not ischemic in nature. Transstenotic pressure gradient determination performed at the time of diagnostic catheterization may provide assistance in clinical decision-making in selected patients with angiographically moderate stenoses.

Ventricular septal defect: Selection of patients and timing for surgery

Eighty-seven patients with isolated ventricular septal defect (VSD) operated on in the first 5 years of life, that had a mean interval of 10 months between diagnostic catheterization and surgery, were studied retrospectively. The size of the VSD was correlated with diagnostic catheterization data and comparative analysis of clinicl findings (ECG and CTR) was made between the time of diagnostic catheterization and just prior to surgery. The study showed that 42 per cent of patients with the ratio of systolic pulmonary artery pressure to systolic systemic artery pressure (Pp/Ps) 0.5 to 0.8 had a marked reduction in size of VSD in a rather short interval of 10 months. In patients with Pp/Ps greater than or equal to 0.8, the incidence of decrease in VSD size was close to nil. The highest incidence of decrease in VSD size was seen in patients with high flow and low resistance. ECG and CTR were very useful diagnostic tools to follow the course of the VSD size. The patients with Pp/Ps 0.5 to 0.8 should be observed for an interval of 10 to 12 months, expecting spontaneous decrease in VSD size. If clinical parameters (ECG, CTR) fail to improve in that interval, then the patients should have surgery. The patients with Pp/Ps greater than or equal to 0.8 should be operated on without delay.

Rapid sequential visualization of the heart and great vessels in man using the wide-field anger scintillation camera. Radioisotope-angiography following the injection of technetium-99m.

The recent development of the instantaneously sensing Anger scintillation camera, capable of recording wide-field radioisotope images from the precordium, and a system for video storage and analysis has provided a means of visualizing the anatomic and hemodynamic features of the heart and great vessels without the hazards involved in introducing a radiopaque agent. Sodium pertechnetate ( 99m TcO 4 - ) produces no cardiocirculatory effects or untoward actions and delivers only 0.13 rads of total body radiation. Following injection, the rapidly changing distribution of radioactivity within the heart is recorded by the scintillation camera-television system which includes no inherent dead time or overlap of the scanned field from frame to frame. Video tape replay is available immediately and sequential integrated pictures are possible at any rate up to 60 sec. Radioisotope images of longer intervals are easily obtained by the integration of successive stop-action fields reproduced on a high resolution television monitor and photographed on rapidly developed film. In addition, the replay may be gated and tracked, allowing selected phases to be integrated and time-concentration curves of blood flow. Five to 10 millicuries of 99m TcO 4 - in 2 to 8 cc were rapidly injected into selected cardiac chambers at the time of diagnostic catheterization in 50 patients with a variety of congenital and acquired forms of heart disease. Movement of radioisotope closely reflected the hemodynamic alterations caused by these conditions, as determined by standard contrast angiocardiography. The radioisotope-angiocardiogram provides a new approach for visualization of the cardiovascular system, does not require the use of radiopaque medium, is safer than angiography, and does not disturb circulatory function.