Correlation of remote ST segment depression and coronary anatomy during acute coronary occlusion.

BACKGROUND: The appearance of remote ST segment depression (RSTD) on an electrocardiogram (ECG) is associated with more extensive infarction and a worse clinical outcome than when RSTD is absent. OBJECTIVE: To determine whether RSTD predicts coronary anatomy during acute coronary occlusion. It was hypothesized that RSTD is associated with the occlusion of a proximal lesion, an extensive artery and an artery without distal collateralization. PATIENTS AND METHODS: In 113 consecutive patients with single vessel disease undergoing percutaneous transluminal coronary angioplasty (PTCA), 12-lead ECGs (recorded at baseline and during balloon inflation) and angiographical data were analyzed independently. Patients with ST segment elevation in the primary territory and RSTD (greater than 1 mm ST depression at 80 ms after the J point) (group A) were compared with patients without RSTD (group B). Proximal lesions were defined as lesions located in the segments proximal to the acute marginal branch, first diagonal artery or first obtuse marginal branch. An extensive right coronary artery (RCA) was one that supplied the posterolateral wall; an extensive left anterior descending (LAD) artery was one that supplied the inferoapical wall; and an extensive circumflex artery was one that supplied the posterior descending artery. RESULTS: Fifty-four patients (48%) had PTCA of the proximal vessels, 43 patients (38%) had extensive target vessels and 11 patients (9.7%) had collaterals. Target vessels included 33% in RCA, 44% in LAD artery and 23% in circumflex artery. Forty-five patients (40%) developed RSTD during balloon inflation (group A). Patients in group A were more likely to have extensive vessels on the angiogram than those in group B (group A 49%, group B 31%; P=0.05). None of the patients in group A had collaterals to the culprit artery, while 16% of patients in group B did (P=0.003). The two groups were not significantly different with respect to the number of proximal lesions (group A 58%, group B 42%; P=0.08). Analysis performed according to the target artery revealed that RSTD was associated with occlusion of an extensive RCA during RCA occlusion (extensive RCA in group A 100%, group B 57%; P=0.006). For the LAD artery, RSTD was associated with proximal lesions (group A 74%, group B 41%; P=0.02) and absence of collaterals (group A 100%, group B 74%; P=0.01). CONCLUSIONS: During acute coronary occlusion, the presence of RSTD on 12-lead ECG was specific for the absence of collaterals. The presence of RSTD during RCA occlusion was strongly associated with an extensive RCA, suggestive of posterolateral wall ischemia. During LAD artery occlusion, the presence of RSTD was associated with proximal occlusion, which resulted in ischemia of the LAD artery and the major diagonal artery territories.

Coronary stenting without predilatation in a broad spectrum of clinical and angiographic situations.

BACKGROUND: Direct coronary stenting without balloon predilatation has the potential benefits of a reduced risk of extended dissections, reduced fluoroscopy exposure, reduced procedural time, and potential cost savings. With the availability of superior stents and delivery systems, we review our experience with direct stent deployments in a large selected patient cohort. METHODS: We prospectively studied 158 consecutive cases of attempted coronary stenting without balloon predilatation over a 1-year period. RESULTS: Indications for the procedure included unstable angina (71%), stable angina (24%) and acute myocardial infarction (5%). Target vessels were the anterior descending artery (56%), right coronary artery (30%), circumflex artery (8%), and vein grafts (6%). Pre-procedural TIMI flows were grade 3 (91.7%), grade 2 (5.8%), grade 1 (1.3%) and 0 (1.3%). Lesion types were graded A (27%), B (61%), and C (12%). Stent types included NIR Primo (80.4%), ACS Multi-Link RX Duet (10.1%), NIR (5.1%), and others (4.4%). Stents ranged from 3.0Eth 4.0 mm in diameter (median = 3 mm) and 8Eth 32 mm in length (median = 16 mm). Stents were successfully deployed in 155 cases (98.1%); 2 (1.3%) required predilatation and 1 (0.6%) deployed stent could not be expanded and was opened by rotablation. All except the rotablator case achieved final TIMI grade 3 flow, and 66% did not require further balloon dilatation. There were no deaths or cases of urgent bypass surgery. Case duration and radiation exposure in direct stenting (32.8 +/- 18.9 minutes and 6.7 +/- 6.2 minutes, respectively) compared favorably to those in a matched group of patients in conventional stenting (47 +/- 18 minutes and 11 +/- 7 minutes) and coronary angioplasty (40 +/- 12 minutes and 10 +/- 6 minutes) for single-lesion cases (p < 0.005). Creatine kinase elevation related to the procedure was observed in 5 patients. Subacute stent thrombosis occurred in 2 (1.3%) cases. CONCLUSION: Direct coronary stenting was successfully and safely accomplished in a variety of clinical situations in selected patients.

Adverse events associated with balloon rupture during percutaneous coronary intervention.

BACKGROUND: Balloon rupture is a potential complication of coronary angioplasty. The literature is inconsistent regarding associated adverse consequences. The experience of St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, with balloon rupture is reviewed. PATIENTS AND METHODS: All patients who underwent percutaneous coronary intervention complicated by balloon rupture at St Paul's Hospital from April 1992 to March 1996 were identified from the hospital's database (Seattle Systems, Seattle, Washington). Procedural logs, database records, clinical charts and all cineangiograms were reviewed in detail. RESULTS: A total of 2984 patients had percutaneous coronary revascularization and 110 patients experienced balloon rupture. These occurred in 101 (92%) native coronary arteries and 9 (8%) occurred in saphenous vein grafts. Stents were deployed in 44 (40%) patients; 34 of the stents used were half Johnson & Johnson PS153 stents (Johnson & Johnson Interventinal Systems, Peterborough, Ontario). An event-free postangioplasty course during the index hospitalization was observed in 102 patients (93%); eight patients (7%) had one or more important adverse events postprocedure. These included three deaths (one following a dissection and out-of-catheterization laboratory occlusion, a second following an abrupt occlusion of another target artery and emergency bypass surgery, and another with cardiogenic shock postmyocardial infarction and an unaltered course following angioplasty); one urgent bypass surgery after a left main dissection; and two nonfatal myocardial infarctions (one patient had tamponade and one patient experienced congestive heart failure). Four of the eight events were directly related to the procedure. The rate of death and emergency bypass surgery with balloon rupture did not differ from that of patients without balloon rupture in the authors' centre (1.8% versus 1.4%, not significant). CONCLUSIONS: The majority of patients did not experience any adverse clinical outcomes and demonstrated good angiographic results after balloon rupture. The data did not detect an excess of major adverse events beyond that expected in a diverse general angioplasty population.

Retrieval and analysis of particulate debris after saphenous vein graft intervention.

OBJECTIVES: This study was designed to evaluate the composition and quantity of particulate debris resulting from vein graft intervention. BACKGROUND: Distal embolization and "no reflow" are frequent and important complications resulting from angioplasty of diseased saphenous vein grafts. Little is known about the composition and quantity of embolic particulate debris associated with vein graft intervention, and no intervention has been shown to protect against its clinical consequences. METHODS: A catheter system, designed to contain, retrieve and protect against distal embolization of this material, was evaluated during 27 percutaneous interventional saphenous vein graft procedures. Clinical, angiographic and pathologic analyses were performed. RESULTS: The duration of distal graft occlusion required to allow intervention and subsequent debris removal was 150 +/- 54 s, decreasing as experience was gained. Thrombolysis in Myocardial Infarction trial (TIMI) flow grade increased from 2.6 +/- 0.8 to 3.0 +/- 0.0. Creatine kinase (CK) rose above normal in three patients (11.1%) exceeding 3x normal in one (3.7%) resulting in the diagnosis of non-Q-myocardial infarction. Particulate material was identified following 21 of 23 procedures suitable for analysis. Particle size was 204 +/- 57 microm in the major axis and 83 +/- 22 microm in the minor axis. Particles consisted predominantly of soft acellular atheromatous material, such as that typically found under a fibrous cap. Semiquantitative analysis suggested that the quantity of particulate material was less following stenting than following balloon dilation. CONCLUSIONS: Particulate matter is commonly present following routine angioplasty and stenting of saphenous vein grafts. Containment, retrieval and analysis of this particulate debris are all feasible. Comparison to prior clinical experience is limited by small sample size. However, to the extent that these particles may contribute to distal embolization, no-reflow and infarction, such a system may contribute to the reduction of complications following vein graft intervention.

Mechanisms, management, and outcome of failure of delivery of coronary stents.

In a single-center experience, initial failure of attempted stent delivery was relatively infrequent (2.7%) but was associated with increased need for urgent coronary bypass surgery. Delivery failure was more likely with coiled stents and dislodgment from the delivery balloon was more likely with hand-mounted or radiolucent stents.

The natural history and rate of progression of aortic stenosis.

One of the challenges in clinical cardiology is to determine the optimal time of valve replacement surgery in patients with aortic stenosis. To meet this challenge, one requires an accurate knowledge of the natural history and rate of progression of the disease. This review will summarize the natural history of aortic stenosis in terms of symptoms, mortality, and stenosis progression.

Groin complications associated with collagen plug closure of femoral arterial puncture sites in anticoagulated patients.

A retrospective study was conducted to determine the frequency and nature of groin complications when the Vasoseal (Datascope Corp., NJ) hemostasis device was used on 204 occasions to enable removal of the groin sheath in anticoagulated patients. The patients had undergone balloon angioplasty (53%), coronary stenting (20%), and diagnostic angiography (27%). Complications included vascular surgery in 5% including 2 embolized collagen plugs, failure to achieve hemostasis (2%), late external bleeding (2%), purulent discharge (1.5%), a minor ooze of blood (7%), hematomas >6 cm (6%), and hematomas < or = 6 cm (7%). One or more complications occurred with 64 of 204 (30.5%) uses. Multivariate analysis identified diagnostic angiography to be associated with a reduced risk of complications [odds ratio (OR) 0.25], while stent procedure (OR 2.7) and female gender (OR 2.5) were associated with increased risk. This complication rate is similar to other reported series except for a higher rate of vascular surgery. The high incidence of anticoagulation in our study patients (94%) may explain this difference. We recommend caution and adherence to the recommended technique when the device is used in anticoagulated patients.

Pullback atherectomy with the Arrow-Fischell atherectomy device.

The Arrow-Fischell pullback atherectomy catheter is designed to circumferentially debulk and retrieve coronary atheroma. We performed pullback atherectomy before balloon angioplasty or stenting in 41 patients. The device crossed the target lesion in 38 (93%) and obtained tissue in 36 (88%). All procedures were completed successfully and without myocardial infarction, emergency cardiac surgery, or death. Complications included major spasm in 8 patients, postprocedural abrupt closure in 1, and otherwise uncomplicated arterial perforation in 2. Pullback atherectomy can be performed relatively safely, but is more difficult than balloon angioplasty, obtains less tissue than directional atherectomy, and is associated with significant limitations.

Early and late assessment of the Micro Stent PL coronary stent for restenosis and suboptimal balloon angioplasty.

This prospective study represents the initial assessment of the Micro Stent PL (Arterial Vascular Engineering, Inc.) coronary stent. From one to three radiopaque stainless steel stents, each measuring 4 mm long, were premounted onto specially designed balloon catheters. A total of 123 stents were implanted in 41 patients without procedural failure or complications. Stent dislodgment proved a concern, with 7 of 123 stents (5.7%) moving > 3 mm from the site of placement and late downstream migration occurring in an additional patient. Subacute stent thrombosis occurred in two patients (5%). Six-month angiographic follow-up was available in 37 of 41 patients (90%). Minimal lumen diameter at baseline was 0.93 +/- 0.51 mm, increasing to 2.74 +/- 0.49 mm after stenting, and falling to 1.66 +/- 0.89 mm at 6 months; this represents a late loss of 60% of the initial gain. Restenosis, based on a binary definition of > 50% diameter stenosis, was documented in 18 patients (49%). Advantages of the Micro Stent PL include its radiopacity and marked ease of distal delivery. The potential for stent dislodgment has implications for future stent designs. The role of the Micro Stent PL in managing restenosis is unclear, but it appears useful in the management of dissection and threatened closure after balloon angioplasty.

From Hippocrates to facsimile. Protecting patient confidentiality is more difficult and more important than ever before.

Although patient confidentiality has been a fundamental ethical principle since the Hippocratic Oath, it is under increasing threat. The main area of confidentiality is patient records. Physicians must be able to store and dispose of medical records securely. Patients should be asked whether some information should be kept out of the record or withheld if information is released. Patient identity should be kept secret during peer review of medical records. Provincial legislation outlines circumstances in which confidential information must be divulged. Because of the "team approach" to care, hospital records may be seen by many health care and administrative personnel. All hospital workers must respect confidentiality, especially when giving out information about patients by telephone or to the media. Research based on medical-record review also creates challenges for confidentiality. Electronic technology and communications are potential major sources of breaches of confidentiality. Computer records must be carefully protected from casual browsing or from unauthorized access. Fax machines and cordless and cellular telephones can allow unauthorized people to see or overhear confidential information. Confidentiality is also a concern in clinical settings, including physicians' offices and hospitals. Conversations among hospital personnel in elevators or public cafeterias can result in breaches of confidentiality. Patient confidentiality is a right that must be safeguarded by all health care personnel.

Effect of rotational atherectomy on quality of life.

OBJECTIVE: To evaluate whether percutaneous coronary rotational atherectomy (RA) improves quality of life. DESIGN: Prospective sequential study of the first 20 patients who had RA at St Paul's Hospital, Vancouver from November 1993 to April 1994. SETTING: Tertiary care teaching hospital. PATIENTS: There were nine males and 11 females with a mean age of 68 +/- 9.3 years. All had angina pectoris with type B or C coronary lesions. INTERVENTIONS: RA was performed using the Rotablator device. RESULTS: The procedure was angiographically successful in 20 patients and clinically successful in 18 patients. Two patients who sustained acute myocardial infarctions underwent coronary bypass surgery. Before RA there was one patient in Canadian Cardiovascular Society angina class I, five patients in class II, 12 in class III, and two in class IV. At six months' follow-up there were 11 patients in class I, seven in class II and two in class III. The mean Duke Activity Status Index improved from 21.3 +/- 15.8 (mean +/- SD) before the procedure to 36.9 +/- 15.8 (P < 0.001) at six months' follow-up. The consumption of anti-anginal medications also decreased. CONCLUSIONS: RA was associated with improved functional status and quality of life in patients having angina pectoris with type B or C coronary lesions.

Usefulness of coronary stenting for cardiogenic shock.

Coronary stenting was performed in 15 selected patients with cardiogenic shock, with favorable clinical and angiographic outcomes. This experience suggests that coronary stenting may play an important adjunctive role in the management of cardiogenic shock and may improve outcome beyond that achieved with balloon angioplasty alone.

Stenting for treatment of coronary vasospasm.

Following an acute anterior myocardial infarction, a 56-yr-old female underwent two balloon angioplasty procedures for a recurrent proximal left anterior descending artery stenosis. She had recurrent angina pectoris. Angiography showed a noncritical restenosis with marked provocable superimposed vasospasm. Despite repeat balloon dilatation and stenting of the lesion, she developed recurrent symptoms. One month later, angiography showed progressive fixed disease and reversible spasm proximal and distal to, but not involving, the stented arterial segment. She underwent single-vessel coronary artery bypass grafting, and is asymptomatic at 6-mo follow-up.

Initial experience using Prostar: a new device for percutaneous suture-mediated closure of arterial puncture sites.

A new device that enables closure of the femoral artery puncture site by percutaneous placement of two nonabsorbable sutures (Prostar) was evaluated. Our initial experience included 32 insertion attempts at 29 femoral arterial puncture sites and one femoral venous puncture site. The device was applied at arterial puncture sites that had been used to carry out 12 balloon angioplasties (41%), seven intracoronary stent placements (24%), five intraaortic balloon pump insertions (17%), four diagnostic angiographies (14%), and one rotational ablation (3%). The venous access site closed was in a patient who had undergone balloon angioplasty and intracoronary thrombolysis. Most patients were anticoagulated with an average activated clotting time (ACT) of 306 +/- 123 sec (12 patients) or an average PTT of 68 +/- 29 sec (14 patients). There were four failures to achieve hemostasis using the device due to: inability to place the device because of peripheral vascular disease, entrapment of cutaneous tissue in the suture, a suture break that prevented hemostasis from being achieved, and avulsion of the sutures from the needles. Although three other suture breaks occurred, these did not prevent hemostasis from being achieved. Thus, 88% (28/32) of attempted uses were successful, and by using a second device in two of the failed attempts, 94% (30/32) of the puncture sites were successfully closed using the device. There was one late rebleed that required 1 hr of groin clamp pressure in an angioplasty patient who had received intracoronary urokinase. An ooze of blood occurred in 4 patients, but in only 2 was this more than trivial, resulting in discontinuation of heparin in one patient and a small hematoma in the other. We conclude that this device can be used safely and effectively, even in fully anticoagulated patients who have undergone complex procedures. The ultimate role of the device will require further experience and appropriate randomized studies.

Multicenter clinical experience with the development of a novel short coronary stent and its prototype device.

Our initial experience with the Micro Stent PL and its prototype intracoronary stent is described. A total of 206 stents were implanted in 84 patients for threatened closure or restenosis following balloon angioplasty. The stenting procedure was successful and uncomplicated in 83 of 84 patients. Potential advantages of this particular stent relate to its short length, low surface area, expandability over a range of diameters, radiopacity, low profile, and ease of delivery.

Use of intra-aortic nitroglycerin in the cardiac catheterization laboratory.

The purpose of this study was to determine whether nitroglycerin (NTG) injected into the ascending aorta or left ventricle would safely and effectively lower blood pressure in hypertensive patients undergoing cardiac catheterization. Fifty bolus injections of 297 +/- 67 micrograms (mean +/- SD) NTG were given to patients with a systolic blood pressure (SBP) of > or = 140 mm Hg (mean SBP 188 +/- 20.1 mm Hg). An average drop in systolic blood pressure of 36 +/- 16 mmHg (P < 0.001), diastolic blood pressure of 19 +/- 7 mm Hg (P < 0.001), and left ventricular end-diastolic pressure of 4.7 +/- 4 mm Hg (P = 0.001) was well tolerated in each patient. The mean time to response was 11 +/- 3 sec. Intra-aortic injection of NTG is a safe and effective means to treat hypertensive patients in the cardiac catheterization laboratory.

Guide wire extension may not be essential to pass an over-the-wire balloon catheter.

The ability to pass an angioplasty balloon catheter over a regular length free guidewire can be advantageous in certain circumstances. This procedure was performed successfully in 99 consecutive patients without any complications. There was improved tactile sense of the lesion and improved dye delivery without the necessity of resorting to the use of extension wires or magnet exchange device. When performed while observing the required precautions this is a safe procedure.

Coronary stenting for acute myocardial infarction.

In summary, our experience suggests that coronary stents may play a useful role in carefully selected patients undergoing angioplasty for myocardial infarction. The potential may exist to increase rates of successful infarct artery reperfusion and increase long-term patency. The use of stents in myocardial infarction should probably be reserved for situations in which balloon angioplasty fails. Newer stent designs and anticoagulant regimens may alleviate some of the current concerns with regard to stenting at the time of acute myocardial infarction.