Comparison of left ventricular systolic and diastolic function in patients with idiopathic dilated cardiomyopathy and mild heart failure versus those with severe heart failure

The pathogenesis of acute pulmonary edema in idiopathic dilated cardiomyopathy (IDC) is not completely understood. Because pulse-wave tissue Doppler imaging (TDI) allows a direct comparison between systolic as well as diastolic wall motion velocities, we tested the hypothesis that acute pulmonary edema is caused by both systolic and diastolic failure. We prospectively studied 65 patients. Forty patients had IDC (group 1), 15 of whom had recent-onset pulmonary congestion (group 1a, New York Heart Association [NYHA] functional classes III and IV) and 25 of whom were in clinically stable condition without signs of pulmonary congestion (group 1b, NYHA I and II). All of these patients were restudied after 3, 7, and 45 days. Groups 1a and 1b were compared with 25 subjects without evidence of heart disease (group 2). Peak systolic wall motion velocity (Vs), peak wall motion velocity of the early (Ve), and late (Va) filling waves were measured by TDI; mitral inflow pattern was determined by pulse-wave Doppler and left ventricular (LV) ejection fraction (EF) by 2-dimensional echocardiography. In those patients without pulmonary edema (controls and group 1b, n = 50), we found a positive correlation between LVEF and Vs (r = 0.72, p <0.001) and between LVEF and Ve (r = 0.79, p <0.001). Early diastolic wall motion velocity always exceeded peak systolic wall motion velocity (Ve/Vs ratio >1). In patients with IDC with recent-onset pulmonary congestion (group 1a), Ve was significantly lower compared with group 1b (3.5 +/- 0.2 vs 4.9 +/- 0.4 cm/s, p <0.01, Ve/Vs ratio <1). Clinical improvement was paralled by a gradual increase in Ve (3.5 +/- 0.2 to 6.8 +/- 0.3 cm/s, p <0.01) but not in Vs or LVEF. Thus, in patients with IDC acute pulmonary edema is exclusively caused by diastolic rather than systolic failure.

Direct assessment of coronary steal and associated changes of collateral hemodynamics in chronic total coronary occlusions

BACKGROUND

Coronary steal can occur in collateral-dependent myocardium during pharmacologically induced vasodilation. This study assessed coronary steal invasively in chronic total coronary occlusions (TCOs).

METHODS AND RESULTS

In 35 consecutive patients with a percutaneous transluminal coronary angioplasty of a TCO (duration >4 weeks), coronary flow velocity (APV) by a Doppler wire and distal pressure (P(D)) by a pressure wire were assessed in the collateral-dependent vascular bed before dilatation. Indexes of peripheral resistance (R(P)) and for the collateral pathway, including the donor artery segment (R(CP)), were calculated. Changes of these parameters were assessed during intravenous adenosine (140 microg x kg(-1) x min(-1)). Adenosine caused a decrease of APV, ie, coronary steal, in 13 patients (37%; group S), an increase in 11 patients (group R), and no change in 11 patients (group N). Angiographic analysis of collateral pathways showed no difference between the groups, except that in group S all collateral connections were continuously visible but no large collaterals (>0.5 mm) were found. In group N, collaterals were least developed. The increase of APV in group R was associated with a decrease of R(P), whereas R(CP) remained unchanged. In contrast, group S showed no change in R(P) but a significant increase of R(CP), indicating an increased resistance of the donor segment.

CONCLUSIONS

Coronary steal is observed in about one third of TCOs and is associated with specific hemodynamic changes of R(P) and R(CP). Steal occurred only with well-developed angiographically visible collaterals but not with very large collaterals.

Perkutane Ballondilatation einer umschriebenen Subaortenstenose

Discrete subaortic stenosis is an uncommon congenital cardiac disorder in which the left ventricular outflow tract is narrowed. We report about the diagnostic procedures and the successful balloon dilatation of a 49-year old, highly symptomatic male patient suffering from discrete subvalvular aortic stenosis.

Collateral function in chronic total coronary occlusions is related to regional myocardial function and duration of occlusion

BACKGROUND

Collateral circulation can maintain myocardial function and viability in chronic total coronary occlusion (TCO). The present study evaluates the relation of myocardial function and duration of occlusion to collateral function.

METHODS AND RESULTS

A total of 50 patients underwent a successful recanalization of a TCO (>4 weeks' duration). Collateral function was assessed by intracoronary Doppler and pressure recordings before the first balloon inflation and after PTCA had been completed. Collateral function was assessed by Doppler- (CFI(D)) and pressure-derived collateral flow indices (CFI(P)), as well as indices of collateral (R(Coll)) and peripheral resistance (R(P)). Patients with normokinesia had lower R(Coll) (4.9+/-2.5 versus 11.8+/-8.2 mm Hg. cm(-1). s(-1); P=0.033) and lower R(P) (3.8+/-1.9 versus 6.1+/-4.1 mm Hg. cm(-1). s(-1); P=0.031) than those with akinesia. Patients with akinesia and a TCO duration of </=3 months had the highest R(Coll) and R(P), whereas those with akinesia and a longer TCO duration had similar collateral function as patients with normokinesia. After PTCA, CFI(D) and CFI(P) decreased from 0.37+/-0.20 to 0.21+/-0.17 (P<0.001) and from 0.44+/-0.12 to 0.36+/-0.11 (P<0.001), respectively, with an increase in R(Coll) of 139+/-128% (P<0.001) and R(P) by 65+/-99% (P=0.003). This attenuation of collateral function was less pronounced with epicardial collaterals than with intramyocardial collaterals.

CONCLUSIONS

Collateral function was better in patients with TCO and normal regional function than in those with impaired regional function. In the latter group, collateral function improvement was time dependent. After recanalization, the recruitable collateral function was attenuated because of an increase of R(Coll) and R(P).

No influence of hemochromatosis-related gene mutations on restenosis rate in a retrospective study of 137 patients after coronary stent implantation

BACKGROUND: Recent publications have shown an increased risk of coronary artery disease and myocardial infarction in patients with alteration of the hemochromatosis-related gene (HFE gene). The HFE gene mutation is associated with elevated iron uptake and serum iron overloading. Iron plays an important role in promoting the oxidation of LDL cholesterol. The iron deposition in the endothelium and in the media is closely associated with the progression of atherosclerosis. However, it is unclear whether the mutation of the HFE gene also influences the rate of restenosis after coronary stent implantation. METHODS: In a retrospective analysis, 137 patients (pts.) who underwent elective coronary stent implantation were angiographically reevaluated after six months. All patients were part of the OPTICUS-study population which investigated optimized stent implantation guided by intravascular ultrasound. Computerized quantitative analysis was performed in all procedures in a double-blinded fashion. At six-month follow-up, DNA fragments containing the substitution of tyrosine for cytosine at codon 282 were amplified by PCR. The results were analyzed by polyacrylamide gel electrophoresis. Statistical analysis was performed by multivariate linear regression. RESULTS: According to the HFE gene polymorphism we formed two subgroups: 129 pts. (94%) did not show changes in HFE gene (NH), 8 pts. (6%) were heterozygous for HFE Cys282Tyr (H). The groups did not differ in age, gender, extent of coronary artery disease, initial degree and length of stenosis and all patients underwent re-angiography. At six-month follow-up the average luminal narrowing in the stented vessel was 36.2 +/- 20.3% in the NH group compared with 27.8 +/- 20.0% in the H group which was statistically not significant (n. s.). The minimal luminal diameter was 1.9 +/- 0.71 mm in the NH group and 2.2 +/- 0.66 mm in the H group respectively (n. s.). 33 pts (26%) in the NH group versus 2 pts (25%) in the H group had >/= 50% diameter narrowing at follow-up (n. s.). The odds ratio of stent restenosis in H patients was 0.932. CONCLUSIONS: The authors did not find any association between restenosis rate and HFE gene alteration and therefore, we conclude that the polymorphism of the HFE gene is not a risk factor for restenosis after coronary stent implantation.

Reversibility of coronary endothelial vasomotor dysfunction in idiopathic dilated cardiomyopathy: acute effects of vitamin C

In patients with idiopathic dilated cardiomyopathy, endothelium vasomotor function is disturbed. Increased oxidative stress and the consecutive formation of oxygen free radicals have been implicated as one possibility for this observation, suggesting that nitric oxide (NO) is inactivated by oxygen free radicals. We tested the hypothesis that the antioxidant, vitamin C, may improve endothelial function in idiopathic dilated cardiomyopathy. In 11 patients, the endothelium-dependent vasomotor response of the left anterior descending coronary artery to intracoronary acetylcholine (ACh) infusion (1/2 x 10(-6) mol/L, 1/4 x 10(-5) mol/L; respectively) was determined before and immediately after intravenous infusion of 3 g of vitamin C. Coronary cross-sectional diameter was obtained by quantitative coronary angiography, average peak velocity was measured by an intracoronary Doppler flow wire, and coronary blood flow (CBF) was calculated. Maximum cross-sectional diameter was determined after administration of nitroglycerin. Dose-dependent ACh showed a decrease in cross-sectional diameter (-5% to -7%, p <0.05) and an increase in average peak velocity (+16% to +25%, p <0.05); the CBF was unchanged (+1% to -2%, p = NS). After vitamin C infusion, the cross-sectional diameter increased in a dose-dependent manner from +11% to +15%, the average peak velocity increased from +20% to + 41% (p <0.05), and the CBF increased from +38% to + 82% (p <0.01, p <0.001, respectively). Thus, patients with idiopathic dilated cardiomyopathy had endothelial dysfunction, and administration of vitamin C reversed endothelium-dependent dysfunction.

Microvascular dysfunction in chronic total coronary occlusions

BACKGROUND

Microvascular dysfunction is defined as reduced coronary flow reserve in the absence of an epicardial stenosis. This study determined its prevalence and relation to regional myocardial function in chronic total coronary occlusions (TCO).

METHODS AND RESULTS

After recanalization and stenting of a TCO (duration, >4 weeks) in 42 patients, coronary flow velocity reserve (CFVR) was measured by intracoronary Doppler. In a subset of 27 patients, intracoronary pressure was recorded to obtain the fractional flow reserve (FFR). In 21 patients, the CFVR was reassessed after 24 hours. CFVR was <2.0 in 55% of all patients. In the subgroup with simultaneous pressure recordings, 52% of patients showed a CFVR<2.0 and a FFR>/=0.75, indicating microvascular dysfunction. Both reduced CFVR and reduced FFR occurred in only 2 patients (7.7%). CFVR and FFR were not correlated (r=0.03). A low CFVR was associated with a higher baseline average peak velocity (35.6+/-16.6 versus 22.4+/-11.5 cm/s; P=0.006). Doppler parameters did not change within 24 hours. Regional dysfunction had no influence on CFVR. Patients with diabetes and/or hypertension had a lower CFVR than those without this comorbidity (1.86+/-0.69 versus 2.36+/-0.45; P<0.05).

CONCLUSIONS

Microvascular dysfunction was observed in 55% of TCOs, independent of the impairment of regional myocardial function. Dysfunction was observed more often in patients with diabetes and hypertension. Neither CFVR or FFR alone is appropriate for assessing angioplasty results in patients with a TCO; CFVR should be combined with FFR to differentiate microvascular dysfunction from residual coronary stenosis or diffuse disease.

Immediate changes of collateral function after successful recanalization of chronic total coronary occlusions

BACKGROUND

Coronary collaterals are essential to maintain myocardial function in chronic total coronary occlusions (TCOs). The aim of the present study was to assess the collateral circulation in TCOs before coronary angioplasty and to determine the recruitable collateral perfusion after recanalization by use of intracoronary Doppler flow velocimetry.

METHODS AND RESULTS

In 21 patients with TCOs (duration >4 weeks), Doppler recordings of basal collateral flow were obtained before the first balloon inflation. Angioplasty was performed with stent implantation in all lesions. At the end of the procedure, recruitable collateral flow was measured during a repeat balloon inflation. The collateral flow index (CFI) was calculated from the velocity integral during the occlusion/velocity integral of antegrade flow. In 17 of 21 patients, angiography was repeated after 24 hours, and CFI was reassessed. Average peak velocity of collateral flow was 10.9+/-5.6 cm/s with a predominantly systolic flow (diastolic/systolic velocity ratio <0.5) compared with antegrade flow (diastolic/systolic velocity ratio >1.5). After recanalization, the average peak velocity of recruitable collateral flow dropped by >50% to 4.7+/-2.5 cm/s. CFI fell from 0.48+/-0.25 to 0.21+/-0.16 (P:<0.001). There was no further change of CFI during the following 24 hours. CFI was higher in patients with preserved regional ventricular function than in those with akinetic myocardium (0.57+/-0.23 versus 0.38+/-0.12, P:<0.05).

CONCLUSIONS

Collateral circulation in TCO provided 50% of antegrade coronary flow. A considerable fraction of collateral flow was immediately lost after recanalization, indicating that TCO may not remain protected from future ischemic events by a well-developed collateral function.

Non-surgical extraction of right cardiac "thrombus in transit"

In two hemodynamically unstable patients, massive pulmonary embolism and free-floating right cardiac thrombi were diagnosed. Thrombolytic therapy was contraindicated and surgical treatment was rejected. In these two cases, we describe a successful non-surgical, percutaneous extraction of mobile right cardiac thrombi. Cathet. Cardiovasc. Intervent. 51:316-319, 2000.

Single-laser approach for fluorescence guidance of excimer laser angioplasty at 308 nm: evaluation in vitro and during coronary angioplasty

BACKGROUND AND OBJECTIVE

Spectroscopic guidance of laser angioplasty has been attempted using a diagnostic He-Cd laser in addition to the therapeutic laser system. This study evaluated a single-laser approach for simultaneous ablation and fluorescence excitation.

STUDY DESIGN/MATERIALS AND METHODS

A spectroscopy system was coupled to a clinical XeCl excimer laser. Ablation of 162 human aortic samples in saline and blood with 45 mJ/mm2 per pulse yielded 676 fluorescence spectra validated histologically. The same equipment was used in 16 patients for angioplasty of 18 coronary stenoses applying 500 to 1,725 pulses with 45 to 60 mJ/mm2 under saline flushing. A total of 783 spectra were recorded and validated by intracoronary ultrasound (categories: atheroma, fibrous plaque, calcified lesion).

RESULTS

In vitro, 5 types of spectra could be differentiated: (1) atheroma, (2) fibrous plaque, (3) calcified lesion in saline, (4) media, and (5) calcified lesion in blood. Discriminant analysis prospectively classified 576 validation spectra with the following sensitivity and specificity for each type: (1) 83.5 and 97.1%, (2) 85.7 and 96.8% (3) 100 and 98.5%, (4) 98.1 and 99.3%, (5) 98.9 and 100%, respectively. In vivo type 1, 2, 3, and 5 spectra were also observed, but not the media spectrum. The predominant sonographic category also prevailed in spectroscopy. Calcified lesions yielded type 3 and 5 as well as mixed spectra.

CONCLUSIONS

Using an excimer laser for angioplasty allows combining ablation and fluorescence excitation without a diagnostic laser. Principal types of atherosclerotic lesions and the media can be differentiated spectroscopically with this approach.

Determinants of stent restenosis in chronic coronary occlusions assessed by intracoronary ultrasound

Chronic coronary occlusions have a high recurrence rate that can be reduced by stenting, but this rate remains higher than in nonocclusive lesions. To analyze possible determinants of restenosis in these lesions, intracoronary ultrasound was performed during the recanalization procedure. A chronic coronary occlusion of > or = 1 month duration (range 1 to 33 months; median 3.3) was successfully recanalized in 41 patients. Quantitative ultrasound analysis was performed before and after stent placement, with measurement of the luminal area, the extent of the plaque burden at the site proximal and distal to the occlusion, and within the occlusion and the subsequent stent. The degree of compensatory enlargement of the coronary artery within the occlusion was determined by comparing the average of the total vessel area of the proximal and distal reference with the lesion site. Early reocclusion (subacute stent thrombosis) was observed in 1 patient (2.4%). The angiographic control after 6 months showed restenosis in 9 patients with 1 late reocclusion. The overall recurrence rate was 24%. There was no difference in clinical and procedural characteristics between lesions with restenosis and without restenosis. The latter had a larger minimum stent area (7.59 +/- 1.96 mm2 vs 5.71 +/- 0.90 mm2; p <0.01), and there was evidence for more compensatory vessel enlargement in lesions without restenosis. Thus, intracoronary ultrasound showed that a smaller minimum stent area was a major predictor of angiographic restenosis, and it occurred more often in occlusions without compensatory vessel enlargement.

[Experiences with temporary vena cava filters in 114 at-risk patients with thrombosis or thromboembolism]

BACKGROUND AND OBJECTIVES

The indications for temporary implantation of a vena cava filter remain unclear and there are as yet few data about its complications and reliability. It was the aim of this study to determine the efficacy and complication rate of the temporary use of a vena cava filter (VCF) in a large group of patients at high risk of pulmonary embolism, and thus contribute to defining the indications for such temporary implantation.

PATIENTS AND METHODS

Between November 1991 and October 1997 a total of 118 VCF were implanted in four groups of a total of 114 patients (67 women, 47 men; average age 45.3 +/- 19.8 [12-82] years) to prevent pulmonary embolism: those (1) with massive or fulminant pulmonary embolism (n = 54); (2) with mechanical thrombus fragmentation and (or) local catheter-delivered systemic thrombolysis in pelvic, leg or caval vein thrombosis (n = 42); (3) with systemic thrombolysis in case of floating thrombi at the femoral, iliac or caval veins (n = 7); and (4) as perioperative measure in caesarean section, venous thrombectomy, other surgical interventions or when anticoagulation had to be discontinued in patients with deep vein thrombosis (n = 11).

RESULTS

Filters remained implanted for a mean of 6.1 +/- 3.4 (1-16) days. Placement had to be corrected because of filter dislocation in eight patients. Proven pulmonary embolism occurred after filter implantation in only one patient, after filter displacement into the unthrombosed contralateral iliac vein. Thrombus deposition on the filter before its removal was demonstrated in nine patients: thrombolysis was effective in seven of them, while thrombosed filters had to be removed surgically in two. Residual thrombi were found on the filter in six further patients. No pulmonary embolism occurred in connection with filter removal. Local complications at or around the site of insertion of the introducing catheter occurred in 53 of the 114 patients (46.5%): haematoma in 42, infection in 21 and brachial vein thrombosis in three patients.

CONCLUSIONS

The rate of clinically relevant pulmonary embolism can probably be reduced to a minimum by the implantation of a temporary vena cava filter. The overall complication rate is high, but serious complications are rare.

[Direct coronary stent implantation without predilatation--a new therapeutic approach with a special balloon catheter design]

Stent implantation serves as the gold standard for proximal lesions of the coronary arteries with a diameter between 2.75-3.5 mm. Our new concept aims at a reduced procedure duration and fluoro-time as well as a decreased ischemic period during stent implantation. A new therapeutic concept of a direct stent implantation without predilatation was tested using a specially developed balloon catheter on which various 14-16 mm long "slotted-tube" stents are mounted between two conical, radiopaque markers. In 105 consecutive patients, who were scheduled for angioplasty, this method of direct stent implantation was performed. Six of the procedures were performed for acute myocardial infarction and 8 in so-called high-risk procedures. The direct stent implantation was successful in 88%. In 6%, predilatation of the lesion site was necessary before stent placement. In the remaining 6%, a stent could not be successfully implanted despite the availability of various other systems. Comparison of the direct stent implantation with conventional stent placement with predilatation revealed that 1) The fluoro-time for direct stent implantation, compared to the conventional method, was 8.4 +/- 4.9 min vs. 13.7 +/- 8.0 min; p < 0.05, respectively. Furthermore, there were less balloons used per lesion for direct stent implantation (1.4 +/- 0.4) compared to the conventional method (1.7 +/- 0.7), but there was not a significant difference. 2) If we compare those patients with successful direct stent implantation with those with the unsuccessful procedures, the latter group had a higher percent of angiographically visible calcification at the site of the lesion (80% vs. 18%; p < 0.01). In addition, these patients had an increased average age (72 +/- 7 vs. 61 +/- 11 yrs; p < 0.01). The success rate of direct stent implantation did not depend on lesion diameter stenosis before PTCA. Stent dislocation was observed in 3.8% of the procedures, and a single case of stent embolism was seen. In conclusion, the direct stent implantation offers the advantages of a shortened fluoro-time, the use of fewer balloons, and has the potential of less ischemic stress compared to the conventional method of stent implantation with predilatation, if old patients with calcified lesions are excluded. This should be proved on a large scale in future studies also considering a learning curve with regard to the new method. Whether this new approach also reduces the restenosis rate, warrants further studies.

Safety of deferring angioplasty in patients with normal coronary flow velocity reserve

BACKGROUND

In the catheter laboratory there is a need for functional tests validating the hemodynamic significance of coronary artery stenosis.

OBJECTIVES

It was the objective of our study to compare the long-term cardiac event rate and the clinical symptoms in patients with reduced coronary flow velocity reserve (CFVR) and standard PTCA with patients with normal CFVR and deferred angioplasty.

METHODS

Our study included 70 patients with intermediate coronary artery stenoses (13 f, 57 m; diameter stenosis >50%, <90%) and an indication for PTCA due to stable angina pectoris and/or signs of ischemia in noninvasive stress tests. CFVR was measured distal to the lesion after intracoronary administration of adenosine using 0.014 inch Doppler-tipped guide wires.

RESULTS

In 22 patients (31%), PTCA was deferred due to a CFVR > or = 2.0 (non-PTCA group). In the remaining 48 patients (69%) mean CFVR of 1.4+/-0.23 (p < 0.001) was measured (PTCA group). CFVR increased to 2.0+/-0.51 after angioplasty. During follow-up (average 15+/-6.0 months), the following major adverse cardiac events (MACE) occurred: in the PTCA group re-PTCA was performed in nine patients (18.8%) because of unstable angina, five patients (10.4%) suffered an acute myocardial infarction (MI) (two infarctions occurred during the angioplasty, three patients suffered an infarction during follow-up), two patients (4.2%) needed blood transfusions due to severe bleedings, two patients (4.2%) underwent bypass surgery and one patient (2.1%) died. In the non-PTCA group, angioplasty was necessary only in two cases (9.1%) during follow-up. We did not observe any MI in the non-PTCA group. The overall rate of MACE was significantly lower in the non-PTCA group compared to the PTCA group (9.1% vs. 33.3%, p < 0.01). However, only 40% of the patients of the non-PTCA group were free of angina pectoris at stress. In the PTCA group, 63% did not complain of any symptoms at follow-up (p < 0.05).

CONCLUSIONS

We conclude that determination of the CFVR is a valuable parameter for stratifying the hemodynamic significance of coronary artery stenosis. PTCA can safely be deferred in patients with significant coronary stenosis but a CFVR > or = 2.0. The total rate of MACE at follow-up was below 10% among these patients. However, if PTCA was deferred the number of patients who are free of angina is lower compared to those patients who underwent angioplasty.

[Percutaneous balloon pericardiotomy for the treatment of a malignant pericardial tamponade]

HISTORY AND CLINICAL FINDINGS

A 72-year old man was admitted because of increasing dyspnoea, failing fitness and weight loss. Physical examination was unremarkable except for decreased heart sounds.

INVESTIGATIONS

He was anaemic (haemoglobin 11.7 g/dl), erythrocyte sedimentation rate was raised (80/90 mm) as was C-reactive protein (169 mg/dl). Chest radiogram showed tent-like widening of the cardiac silhouette and a 6 cm space-occupying lesion in the left hilus. Echocardiography revealed pericardial effusion of up to 2.3 cm (epi- to pericardium).

TREATMENT AND COURSE

Because of an increase in dyspnoea and pericardial effusion a pericardiocentesis was performed. This fluid and needle biopsy of the space-occupying lesion revealed small-cell carcinoma. 6 days after the pericardiocentesis the dyspnoea further increased as did the pericardial effusion (to 3.9 cm). Percutaneous balloon pericardiotomy was uneventfully performed. During a follow-up period of 14 months there were no further pericardial effusions.

CONCLUSION

Percutaneous balloon pericardiotomy can be undertaken as a minimally invasive treatment of symptomatic pericardial effusion. It should be considered as an alternative to surgical creation of a pericardial window, especially in very ill patients.

Direct coronary stenting without predilatation: a new therapeutic approach with a special balloon catheter design

Coronary stenting is the primary therapeutic option for many coronary lesions, after the risk of subacute stent thrombosis and bleeding complications has been reduced by antithrombotic regimens and improved stent expansion. It would be desirable to shorten the procedure and the duration of ischemia, and to reduce the risk of ischemic complications during balloon inflation by implanting the stent without previous dilatation of the lesion. This is not possible with the presently available stent delivery systems. This new therapeutic concept was tested with a specially designed balloon catheter, on which slotted-tube stents can be fixed between two conical radiopaque markers. Sixty-one patients eligible for angioplasty underwent direct stent implantation without predilatation. Four procedures were performed for acute myocardial infarction, and two as high-risk PTCA. Single slotted-tube stents (Palmaz-Schatz, NIR, or JOStent) of 14-16-mm length were mounted between the conical radiopaque markers of a special balloon which provided a fixation for the crimped stent. The direct implantation was successful in 80% of all patients, while in 10% the stent could be deployed after predilatation of the lesion. In 10% of lesions a stent could not be implanted with this and any other delivery system. When patients with successful direct stenting were compared with those with indirect (after predilatation) or unsuccessful stent deployment, the presence of angiographically visible calcification was higher in the unsuccessful cases (75% vs. 19%; P < 0.01), and the patients were older (72+/-8 vs. 61+/-12 years; P < 0.01). Radiation exposure time was only 8.7+/-5.1 min as compared with 12.6+/-7.6 min in conventional stent procedures with predilatation (P < 0.05). The number of balloons used per lesion was also lower than with conventional stenting. Stent dislocation was observed in 5%, and no embolization occurred. The new therapeutic approach of direct stenting without predilatation proved to be a safe and successful procedure in this initial series of coronary angioplasties. When calcified coronary lesions are avoided, it provides a way to rationalize stent implantation with shorter radiation exposure times, fewer balloons, and the potential advantage of fewer ischemic complications as no balloon predilatation is required.

Complications of intra-aortic balloon counterpulsation. The role of catheter size and duration of support in a multivariate analysis of risk

AIMS

The aim of this study was to assess the risk of intra-aortic balloon counterpulsation and to identify clinical and procedural variables that would predict complications.

METHODS AND RESULTS

We analysed 381 consecutive patients who were treated between 1977 and 1995 at our catheterization laboratory and/or medical intensive care unit. The complications considered relevant were limb ischaemia requiring catheter removal, vascular injury, bleeding requiring transfusion, embolic events, and infection. In eight patients the balloon could not be inserted. The rate of complications for the remaining 373 patients was 12.9%. Between 1977 and 1980, surgical insertion was performed using a 12 French catheter with a complication rate of 30.4% (seven of 23 patients). Percutaneous implantation, performed after 1981, had an overall complication rate of 11.7% (41 of 350 patients). Using thinner catheters for percutaneous placement was associated with a reduction in the rate of complications, from 20.7% (17 of 82 patients) for 12 French catheters to 9.9% (10 of 101 patients) for 10.5 French catheters (P = 0.04), and 8.4% (14 of 167 patients) for 9.5 French catheters (P = 0.006). Multivariate logistic regression analysis identified duration of counterpulsation > 48 h (odds ratio 3.6), catheter size (odds ratio 3.4 for 12 French catheters), peripheral vascular disease (odds ratio 2.7), and shock (odds ratio 2.0) as independent risk factors for counterpulsation-associated complications. When considering 9.5 French catheters only (167 patients, all after 1992), the sole remaining independent risk factor was duration of counterpulsation > 48 h (odds ratio 3.8). Those patients with 9.5 French catheters in whom counterpulsation did not exceed 48 h had a low complication rate of 3.9%.

CONCLUSION

The rate of percutaneous intra-aortic balloon counterpulsation complications was thus significantly reduced by employing thinner catheters. It was at an acceptable level for 9.5 French catheters, where a long duration of counterpulsation emerged as the most significant factor associated with complications. Whether using even thinner catheters in combination with a sheathless implantation technique further minimizes the risk of counterpulsation remains to be seen.

Risk factors for acute and subacute stent thrombosis after high-pressure stent implantation: a study by intracoronary ultrasound

BACKGROUND

In the era of coronary stenting with high-pressure expansion, stent thrombosis remains a major life-threatening risk. Because of its superior imaging mode, intracoronary ultrasound could provide insight into potential risk factors for stent thrombosis.

PATIENTS AND METHODS

In 215 patients with stent implantations controlled by intracoronary ultrasound, four occurrences of subacute stent thrombosis, two complete acute thrombotic occlusions, and four occurrences of incomplete acute thrombosis were observed. All stents were expanded with inflation pressures of at least 14 atm ( 17+/-3 atm). The clinical data and the qualitative and quantitative ultrasound information were compared between stents with thrombosis and stents without thrombosis. The luminal area and the plaque border of the reference segments, and of the smallest and largest site of the stented segment after the initial and final expansion, were measured.

RESULTS

Stents in the left anterior descending artery were more often involved in stent thrombosis than other vessels, but the vessel dimensions in this target vessel were smaller than in the right coronary artery. The plaque burden was considerably larger after stent implantation with subsequent thrombosis compared with no thrombosis (74.1+/-8.8% vs 63.6+/-8.0%; p < 0.001), and the stent area was smaller (4.80%+/-1.33 mm2 vs 6.86+/-2.08 mm2; p < 0.01 ). In stents with thrombosis the plaque burden of the stent site with the smallest and largest lumen differed by 15.2%, whereas the difference in plaque burden in stents without thrombosis was 2.7%. Intracoronary ultrasound showed that the best risk predictor of thrombosis was the residual plaque burden of the stented segment (odds ratio 15.7 [confidence interval 2.4 to 104.7]), and a small stent area after implantation (odds ratio 6.8 [confidence interval 1.9 to 24.3]).

CONCLUSION

In a multivariate risk analysis plaque burden was the strongest independent risk factor for stent thrombosis. The amount of residual plaque mass around the stent might be a potential trigger for thrombus formation.

Thrombus formation on transcatheter ASD occluder device in a patient with coagulation factor XII deficiency

Transcatheter occlusion of cardiac defects has become an effective and less invasive alternative to open heart surgery. Thromboembolic complications are rare events, after both surgical and transcatheter closure of atrial septal defects [Galal et al.: Eur Heart J 15:1381-1384, 1994]. We report on a case of thrombus formation on the atrial septal defect occluder system (ASDOS) [Sievert et al.: Cathet Cardiovasc Diagn 36:232-240, 1995; Hausdorf et al.: Heart 75:83-88, 1996]. Two days after transcatheter occlusion, the patient suffered an acute stroke due to embolism despite anticoagulation with intravenous heparin. A coagulation disorder with reduced factor XII concentration was deduced as the likely cause. Repeated transesophageal echocardiographic (TEE) studies revealed an involution of the intracardial thrombus within weeks of subsequent anticoagulatory treatment. First off, this case shows that patients with factor XII deficiency are at risk for thromboembolism. Second, it again clarifies that even large amounts of intraartrial thrombotic material may not be seen by transthoracic echocardiography (TTE) and underscores the necessity of performing TEE. Screening patients for coagulation disorders (Quick's value (Q), partial thromboplastin time (PTT)) before they are selected for treatment with thrombogenic devices is indispensable. With regard to their personal history (earlier thromboembolism) and the result of this screening (e.g., prolongation of PTT), quantitative determination of coagulation factors is reasonable. If patients endangered by thromboembolic complications nevertheless undergo ASD occlusion procedures, anticoagulation monitoring requires exceptional attention. Furthermore, it is recommended that TEE should be carried out in these patients 2 days after treatment, since transthoracic echocardiography (TTE) might be unable to detect thrombus formation on the device.

Complete morphologic and functional resolution of endocarditis of a Toronto stentless porcine bioprosthesis: a study by serial transesophageal echocardiography

Prosthetic valve endocarditis is a serious complication after valve replacement with an incidence of 0.8% for both mechanical and bioprosthetic valves. The new Toronto stentless porcine valve (SPV) for aortic replacement offers promising early results in hemodynamics and a low incidence of valve-related complications. The yearly incidence of bacterial endocarditis was reported to be 1% to 1.5%. Though complications such as a perivalvular abscess or anular dehiscence require immediate surgery, a conservative management of infective endocarditis may be possible in carefully selected cases. This is the case of a patient with late prosthetic valve endocarditis of a Toronto SPV bioprosthesis, who, in spite of large vegetations on all three valve cusps, responded well to conservative treatment. This response was monitored through repeated transesophageal echocardiographic studies (TEE), which documented complete functional recovery of the valve.