Clinical outcome of deferring angioplasty in patients with normal translesional pressure-flow velocity measurements.

OBJECTIVES: The objective of this study was to determine the feasibility, safety and outcome of deferring angioplasty in patients with angiographically intermediate lesions that are found not to limit flow, as determined by direct translesional hemodynamic assessment. BACKGROUND: The clinical importance of some coronary stenoses of intermediate angiographic severity frequently requires noninvasive stress testing. Direct translesional pressure and flow measurements may assist in clinical decision making in patients with such stenoses. METHODS: Translesional spectral flow velocity (Doppler guide wire) and pressure data were obtained in 88 patients for 100 lesions (26 single-vessel and 74 multivessel coronary artery lesions) with quantitative angiographic coronary narrowings (mean +/- SD diameter narrowing 54 +/- 7% [range 40% to 74%]). Target lesion angioplasty was prospectively deferred on the basis of predetermined normal values, defined as a proximal/distal velocity ratio < 1.7 or a pressure gradient < 25 mm Hg, or both. Patients were followed up for 9 +/- 5 months (range 6 to 30). RESULTS: In the deferred angioplasty group, translesional velocity ratios were similar to those of a normal reference group (mean 1.1 +/- 0.32 vs. 1.3 +/- 0.55) and significantly lower than those of a reference cohort of patients who had undergone angioplasty (2.27 +/- 1.2, p < 0.05). The mean translesional pressure gradient in the deferred angioplasty group was also lower than that in the angioplasty group (10 +/- 9 vs. 45 +/- 22 mm Hg, p < 0.001). At follow-up in the deferred angioplasty group, four, six, zero and two patients, respectively, had had subsequent angioplasty, coronary artery bypass graft surgery or myocardial infarction or had died. In one patient, death was related to angioplasty of a nontarget artery lesion, and one patient with multivessel disease had a cardiac arrest due to ventricular fibrillation 12 months after lesion assessment. Among the 10 patients requiring later angioplasty or coronary artery bypass grafting, only six procedures were performed on target arteries. No patient had a complication of translesional flow or pressure measurements. CONCLUSIONS: These data demonstrate the safety, feasibility and clinical outcome of deferring angioplasty of coronary artery narrowings associated with normal translesional coronary hemodynamic variables. Given the practice of performing angioplasty without ischemic testing or when testing is inconclusive, translesional hemodynamic data obtained at diagnostic catheterization can identify patients in whom it is safe to postpone angioplasty.

Right coronary artery occlusion secondary to blunt trauma.

The heart lies in a vulnerable position when the chest is subjected to direct blunt trauma. Acute occlusion of a coronary artery from blunt chest trauma is rare, with occlusion of the right coronary artery at its origin recorded only twice in the English literature. A young male unrestrained driver sustained an acute deceleration injury with significant chest trauma when he crashed, crushing the steering wheel against his chest. Creatine phosphokinase isoenzymes were initially 2% of the total and 8% 12 h later. There were marked electrocardiographic changes, and an echocardiogram revealed abnormal left ventricular systolic function with an akinetic inferior-posterior wall and right ventricular enlargement. A wide mediastinum and mechanism of injury led to the performance of aortography which failed to disclose a right coronary vessel. Subsequently coronary angiography confirmed acute occlusion of the proximal right coronary artery. Because of other associated injuries, nonoperative medical management was successfully utilized.

Is the grading of breast carcinomas affected by a delay in fixation?

The effect of delay in fixation on the modified Bloom and Richardson grade of eight breast carcinomas was investigated. Topologically shuffled samples of each tumour were immersed in fixative at times of 0.5, 2, 4, 6, 18 and 24 h after surgical removal. The grade of each tumour was assessed at delays of 0.5 and 6 h. The tubule formation and nuclear pleomorphism components of the grade showed no change with a delay in fixation of 6 h. The number of mitotic figures declined by a mean of 53% over the same period and this resulted in a decrease in the histological grade of one of the tumours. The implications of these findings for the handling of breast specimens in a diagnostic histopathological laboratory are discussed.

Limitations of translesional pressure and flow velocity for long ostial left anterior descending stenoses.

Translesional pressure and flow velocity can be used to assess angiographically intermediate or indeterminate lesions. Ostial narrowings and long lesions represent situations that may require both pressure and flow velocity assessment. In patients with hypertension, diabetes mellitus, and chronic renal failure, distally measured absolute and regional coronary reserve values alone may not be helpful in selecting lesions requiring intervention.

Conservative management of guidewire coronary artery perforation with pericardial effusion during angioplasty for acute inferior myocardial infarction.

A wire perforation of a totally occluded right coronary artery was treated successfully with prolonged balloon inflation. This non-surgical management is preferred if physiologic and anatomic conditions are suitable.

Approach to total occlusion of an aorto-ostial "Y" saphenous vein graft with anterior descending graft limb stenosis by serial balloon angioplasty and elective stent deployment.

Coronary revascularization using balloon angioplasty and stent placement for unstable angina was performed in a 74-year-old woman with an aorto-ostial occlusion of a "Y-type" saphenous vein graft and a severe stenosis in the body of a 14-year-old left anterior descending saphenous vein graft. Multiple prior coronary bypass graft surgeries, location of branch graft lesions, and length of the ostial stenosis must be considered in selecting the approach to revascularization.

Intraaortic balloon pump support during high-risk coronary angioplasty.

Intraaortic balloon pump support has been demonstrated to be of clinical benefit when used therapeutically and prophylactically in high-risk patients undergoing percutaneous transluminal coronary angioplasty (PTCA). Afterload reduction and post-PTCA-enhanced coronary blood flow afforded by diastolic augmentation during intraaortic balloon pumping provides hemodynamic stabilization, attenuates clinical perturbations of myocardial ischemia, and may provide an important 'bridge' to emergent coronary bypass surgery following abrupt vessel closure complicating PTCA. Recent studies demonstrate a reduction in cardiac morbidity and improved coronary artery patency among patients receiving prophylactic intraaortic balloon pumping after establishing infarct artery reperfusion during acute cardiac catheterization for acute myocardial infarction. A modest increase in cardiac output (20-30%), the requirement of a stable, regular cardiac rhythm, peripheral vascular disease and aortic insufficiency limits the use of intraaortic balloon pump support in relatively few patients. These studies demonstrate that intraaortic balloon counterpulsation provides an effective and safe form of mechanical support in many high-risk patients undergoing PTCA.

Application of intracoronary flow velocity for detection and management of ostial saphenous vein graft lesions.

Ostial lesions of saphenous vein grafts can be difficult to assess by angiography. A physiologic approach to the selection and recanalization of ostial lesions in saphenous vein grafts may be advantageous to overcome limitations of angiography. To assist in identifying favorable physiology and facilitate procedural decision making, the use of coronary flow velocity measurements with a Doppler-tipped 0.018-inch angioplasty flowire in three particularly difficult patients with varying types of saphenous vein graft aorto-ostial narrowings is reported.

Use of translesional coronary flow velocity for interventional decisions in a patient with multiple intermediately severe coronary stenoses.

Translesional pressure gradients are currently not performed routinely for most angioplasty procedures because of the technical limitations. With the use of an 0.18 inch Doppler flow velocity guidewire, coronary flow velocity, both proximal and distal to a lesion, can be easily assessed. In branching arteries, significant lesions are characterized by a ratio of proximal to distal flow velocity of > 1.7, loss of the normal phasic diastolic predominant flow velocity pattern, and/or loss of distal hyperemia. We describe the use of coronary flow velocity in assisting important decision making in a young patient with a recent myocardial infarction and multiple coronary lesions. The decision for angioplasty of the hemodynamically significant stenosis was confirmed by translesional flow velocity measurements. A rational approach to coronary intervention in patients with multiple stenoses of intermediate severity appears to be facilitated by direct measurement of translesional flow dynamics.

Interventional physiology. Part XVIII: Influence of intra-aortic balloon counterpulsation and collateral flow reversal during multivessel angioplasty.

Flow velocity changes during multivessel angioplasty suggests that collateral flow has an important role in determining safety and ischemic threshold during these procedures. The physiology of collateral flow with and without intra-aortic balloon pumping has been demonstrated in this individual and provides insight into the mechanisms of reduced ischemia during high-risk coronary interventions.

Patterns of phasic coronary collateral flow velocity in patients.

Antegrade or retrograde collateral flow velocity Doppler signals, acquired with the flowire, permit the quantitation of collateral blood flow and its phasic patterns. The velocity spectra are easily visualized, and reproducible alterations during balloon occlusion may be directly related to coronary collateral flow-dependent variables of ischemia and left ventricular wall motion. The effects of pharmacologic stimulation on collateral flow remain under study.

Quantitative demonstration of dipyridamole-induced coronary steal and alteration by angioplasty in man: analysis by simultaneous, continuous dual Doppler spectral flow velocity.

In the course of studying the effects of coronary angioplasty on branch vessel flow using two Doppler flow velocity guidewires, we quantitated simultaneous blood flow responses proximal and distal to a stenosis. The alterations of flow documented a horizontal epicardial steal induced during dipyridamole hyperemia, hyperemic flow reversal by intravenous aminophylline, and subsequent normalization of distal hyperemia after endoluminal enlargement by successful angioplasty. The quantitative physiology of the patient described here confirms one postulated mechanism of abnormal myocardial perfusion stress scintigraphy. Continuous dual flowire spectral coronary flow determinations appear to be a valuable method in verifying postulated mechanisms of various pharmacologic and mechanical stimuli influencing coronary blood flow in patients with atherosclerotic coronary artery disease.

Continuous coronary flow velocity monitoring during coronary interventions: velocity trend patterns associated with adverse events.

Continuous measurement of blood flow velocity during interventional procedures has the potential to provide an early warning of coronary flow instability, which can lead to abrupt closure or other adverse events before angiography. The magnitude and fluctuations of the average velocity over time (trend) was studied by using a 0.018-inch Doppler-tipped angioplasty guide wire in 32 patients after coronary angiography (n = 20), atherectomy (n = 2), urgent stent (n = 6), urgent vein graft thrombolysis (n = 4), or acute myocardial infarction (n = 2). The patients (mean age 60 +/- 11 years) had postprocedural in-laboratory flow monitoring for a mean of 19 +/- 11 (range 8 to 36) minutes. The coronary artery monitored was the left anterior descending in 13, circumflex in 6, right coronary artery in 9, and saphenous vein graft in 4. Seven patients had flow-related events during continuous flow velocity monitoring before serial angiographic study. These events included coronary vasospasm (abrupt flow acceleration), vasovagal flow cessation, cyclical flow variations resulting from accumulation of intraluminal thrombus, and rapid decline of flow velocity. The last two patterns were associated with abrupt vessel closure during angioplasty. Continuous flow velocity monitoring is easily incorporated into routine interventional procedures and provides an early indication of unstable flow and the potential for abrupt vessel closure and other adverse events.