[Treatment strategies for chronic total occlusion: current status and outlook]. / Therapie des chronischen Koronararterienverschlusses : Aktueller Stand und Perspektiven.

The present article discusses the current status of treatment strategies for chronic total occlusion (CTO) and the prospects offered by new therapies. The indication for revascularisation recognized in the current European guidelines includes the presence of typical symptoms and evidence of ischemia of over 10% of the total myocardium, while in patients with multiple vascular diseases the aim is complete revascularisation. Although the vast majority of patients with CTO fulfil these criteria, they are currently not receiving interventional treatment as frequently as expected. The reasons often given for this include the low success rates and high recurrence rates. However, both problems have been improved by drug-eluting stents (DES) on the one hand and by wire techniques and strategies on the other, such that results almost comparable with non-occluded coronary lesions can be achieved. While more advanced approaches like retrograde recanalization should be restricted to specialized centres, marked improvements can be achieved even without these special techniques by means of consistent further training and the application of modern techniques. Despite the aggressiveness of these approaches to pass through an occluded artery, the complication rate is not higher than with non-occluded lesions when the specific complications of recanalization are avoided in a careful approach. Further technical improvements are expected with the use of modern imaging techniques such as intravascular ultrasound and high-resolution CT imaging of coronary arteries.

Impact on adenosine stress cardiac magnetic resonance for recanalisation and follow up of chronic total coronary occlusions.

OBJECTIVE: To evaluate the impact on cardiac magnetic resonance imaging (CMRI) with adenosine stress and delayed enhancement for indication and follow up after interventional recanalisation of chronic total coronary occlusions (CTOs). MATERIAL AND METHODS: Twenty consecutive patients (15 males; 5 females; mean age 65 years) with CTO verified by cardiac catheterisation referred to CMRI. Sixteen of them got CMRI before and after coronary recanalisation. Wall motion abnormalities (WMAs), first pass perfusion with adenosine and viability were assessed using a 1.5 T MR scanner (Sonata; Siemens). CMRI results were compared with clinical classifications, the results of cardiac catheterisation and follow up angiography. RESULTS: Sixteen patients had a successful recanalisation, 15 of the occluded coronary artery and one of collateral donor artery stenosis. After recanalisation all stress-induced progressive or new wall motion abnormalities (WMAs) of the corresponding segments and in the collateral donor territory (5 patients) and all adenosine induced perfusion defects (PD) or delay (12 patients) were regredient. 13/16 patients showed no transmural and one patient transmural delayed enhancement (DE) indicating myocardial scar. In 10/16 patients CSS grading of angina improved after recanalisation. CONCLUSION: After successful recanalisation of CTOs, patients with preinterventional stress-induced PDs and WMAs in viable myocardium did not display any signs of stress-induced ischemia postinterventionally. A comprehensive CMRI approach, including assessment of rest and stress WMAs, first pass perfusion and myocardial viability represents an important tool for the pre-interventional decision to recanalise CTOs and follow up.

Treatment with granulocyte-colony stimulating factor in patients with acute myocardial infarction. Evidence for a stimulation of neovascularization and improvement of myocardial perfusion.

BACKGROUND: Stem cell therapy has been suggested to be beneficial in patients after acute myocardial infarction (AMI). Strategies of treatment are either a local application of mononuclear bone marrow cells (BMCs) into the infarct-related artery or a systemic therapy with the granulocyte-stimulating factor (G-CSF) to mobilize BMCs. Nevertheless, the mechanisms responsible for improvement of cardiac function and perfusion are speculative at present. This study has been performed to investigate the effect of G-CSF on systemic levels of vascular growth factors and chemokines responsible for neovascularization, that might help to understand the positive effects of a G-CSF therapy after AMI. METHODS AND RESULTS: Five patients in the treatment group and 5 patients in the control group were enrolled in this study. The patients in the treatment group received 10 microg/kg bodyweight/day of G-CSF subcutaneously for a mean treatment duration of 6.6 +/- 1.1 days. In both groups, levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and monocyte chemotactic protein-1 (MCP-1) were measured on day 2 to 3 and day 5 after AMI. The regional wall perfusion and the ejection fraction (EF) were evaluated before discharge and after 3 months with ECG-gated MIBI-SPECT and radionuclide ventriculography, respectively. Significant higher levels of VEGF (p < 0.01), bFGF (p < 0.05) and MCP-1 (p < 0.05) were found in the treatment group compared to the control group. Levels of VEGF and bFGF remained on a plateau during the G-CSF treatment and decreased significantly in the control group. The wall perfusion improved significantly within the treatment group and between the groups (p < 0.05), respectively. The EF improved significantly within the treatment group (p < 0.05), but the change of the EF between the groups was not significant. CONCLUSION: In patients with AMI, the treatment with G-CSF modulates the formation of vascular growth factors that might improve neovascularization and result in an improved myocardial perfusion and function.

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

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.

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.

Immunoscintigraphy using technetium-99m-labeled anti-NCA-95 antigranulocyte antibodies as an adjunct to echocardiography in subacute infective endocarditis.

OBJECTIVES: This study was performed to assess the clinical value of immunoscintigraphy in subacute infective endocarditis. BACKGROUND: Radiolabeled granulocytes can reveal inflammatory lesions. METHODS: Using technetium-99m-labeled anti-NCA-95 anti-granulocyte antibodies, planar scintigraphy and single-photon emission computed tomography of the thorax were performed in 72 consecutive patients with suspected endocarditis. Each patient also underwent transthoracic and, if findings were negative, transesophageal echocardiography. RESULTS: Thirty-three patients were found to have endocarditis on the basis of clinical criteria (surgical confirmation in 17 patients), and the remaining 39 served as control subjects. Initial scintigraphy was true positive in 26 patients (sensitivity 79%) and false positive in 7 (specificity 82%). Echocardiography was true positive in 29 patients (sensitivity 88%) and false positive in 1 (specificity 97%). Scintigraphy was positive in the four patients with false negative echocardiography, and echocardiography was positive in the seven patients with false negative scintigraphy. Thus, the combination of scintigraphy and echocardiography yielded a sensitivity of 100% and a specificity of 82%. In 10 of the 11 patients with two to three follow-up studies, scintigraphy became negative parallel to clinical improvement, indicating decreasing floridity of the inflammatory process. CONCLUSIONS: Immunoscintigraphy in patients with subacute infective endocarditis provides valuable diagnostic information in equivocal echocardiographic findings and may be used to monitor antibiotic therapy.

Infective endocarditis in the elderly in the era of transesophageal echocardiography: clinical features and prognosis compared with younger patients.

PURPOSE: Advanced age is considered to be associated with a more severe prognosis in infective endocarditis (IE), which is relevance in view of a change in epidemiology of the disease with an increasing proportion of elderly people. We wanted to examine whether in the era of improved diagnostic sensitivity for IE by transesophageal echocardiography the clinical course in elderly persons would be still more severe than in younger patients. PATIENTS: During the period from 1989 to 1993, 104 patients with 106 episodes of IE were treated at our university hospital. Three groups were compared: group A with 28 patients younger than 50 years, group B with 58 patients aged 50 to 70, and group C with 20 patients older than 70. Transesophageal echocardiography was performed in 78% of the patients; it was not performed in 22% of the patients with a conclusive transthoracic examination. The patients were followed up for an average of 25 months after the diagnosis. RESULTS: No significant differences were observed among the age groups with respect to the possible source of infection, the frequency of positive blood cultures, and the type of infective organisms. Elderly patients more often had predisposing valvular conditions (eg, degenerative and calcified lesions and prosthetic valves), which decreased the sensitivity of transthoracic echocardiography to 45% as compared with 75% in group A. Transesophageal echocardiography improved the diagnostic yield by 45% in group C and by 47% in group B. Vegetations were smaller in group C and B as compared with group A, whereas other echocardiographic characteristics were similar. Fever and leukocytosis were less frequent in group C (55% and 25%, respectively) than in group A (82% and 61%, respectively). The interval between the onset of symptoms and the diagnosis of IE was similar in all groups. Elderly patients underwent surgical therapy as frequently (65%) as the other groups. The 1-year survival in group C (26%) was comparable with that in group A (22%) and group B (22%). The major determinant of survival was the occurrence of embolic complications. CONCLUSION: Infective endocarditis in elderly patients caused less severe clinical symptoms than in young patients. The early diagnosis in elderly patients was facilitated by the high sensitivity of transesophageal echocardiography, which enabled the timely initiation of an appropriate medical and surgical therapy. This led to a clinical outcome similar to that for younger patients.

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.

Cheyne-Stokes respiration and prognosis in congestive heart failure.

Patients with congestive heart failure (CHF) frequently demonstrate Cheyne-Stokes respiration (CSR) with repetitive arousals and oxygen desaturations during sleep. Although it was evident from early publications that CSR during the daytime is a poor prognostic indicator in patients with CHF, it was speculated recently that CSR occurring during sleep could impede left ventricular function and even survival. We therefore followed up 36 patients with CHF and a left ventricular ejection fraction < or = 40% who underwent a sleep study at our institution. The patients showed a reduced ejection fraction (20 +/- 8%) and CSR with a median of 19% of total sleep time (lower and upper quartiles 9% and 56%). In 12 +/- 9% of their time in bed, the arterial oxygen saturation was <90%. No patient was lost to follow-up, which lasted for 32 +/- 15 months (range 11 to 53). One-year survival was 86 +/- 6%, and 2-year survival was 66 +/- 8%. Univariate comparisons for survival between groups stratified by the amount of CSR revealed no significant difference (log rank test, p = 0.84). However, the 20 patients with a left ventricular ejection fraction <20% had a shorter mean survival time than patients with an ejection fraction >20% (9.5 vs 28.3 months; log rank test, p = 0.013). Two patients with CSR during the daytime died within 1 month. No other patient had CSR during the daytime, and only 1 patient without daytime CSR died within 1 month (chi-square test, p <0.001). Higher age, reduced carbon dioxide end-tidal partial pressure, and increased transit time were found to be significantly related to the amount of nocturnal CSR. In conclusion, CSR occurring during sleep has no important prognostic impact in patients with CHF, but CSR present during the daytime suggests a high likelihood of dying within a few months.

Prognostic value of Doppler echocardiographic assessment of left ventricular filling in idiopathic dilated cardiomyopathy.

The relation of left ventricular (LV) diastolic filling with the clinical outcome in patients with idiopathic dilated cardiomyopathy (IDC) was examined. LV diastolic filling was assessed by Doppler echocardiography in 57 patients with IDC at the time that the diagnosis was established by angiocardiography. Patients were followed for 29 +/- 16 months. Fifteen patients died: 12 due to progressive congestive heart failure and 3 suddenly. Four other patients underwent cardiac transplantation because of progressive heart failure (1-year survival 86%). Patients who died of congestive heart failure or underwent cardiac transplantation had a steep increase and decrease in the early filling phase as compared with survivors; the peak early Doppler velocity was higher (0.84 +/- 0.16 vs 0.65 +/- 0.21 m/s; p < 0.005), and the deceleration time of the early velocity peak was shorter (117 +/- 26 vs 188 +/- 62 ms; p < 0.001) than in survivors. Surviving patients and those who died suddenly showed similar patterns of LV filling. Deceleration time and peak early Doppler velocity were the strongest predictors of survival as compared with systolic function and clinical status in a Cox proportional-hazards analysis. Patients with a shortened deceleration time (< or = 140 ms) had a significantly reduced 2-year survival rate of 52% (confidence interval 34 to 71%) as compared with those with a longer deceleration time (94%; confidence interval 89 to 98%) (p < 0.001). Evidence was presented for a relation between LV filling and survival in patients with IDC.

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.

Recanalization of chronic total coronary arterial occlusions by percutaneous excimer-laser and laser-assisted angioplasty.

A low primary success and high restenosis rate after recanalization of chronic total occlusions by conventional coronary angioplasty have encouraged the application of new interventional techniques like excimer-laser angioplasty. In 39 patients with a coronary occlusion for 1 to 12 months, recanalization was attempted by laser angioplasty through a multifiber-catheter coupled to a pulsed XeCl excimer laser. After successful passage of the occlusion by a standard guidewire in 27 patients (69%), the laser catheter was advanced over the central guidewire and crossed the occlusion in 25 patients (64%). In 2 patients with unsuccessful passage of the laser catheter, the subsequent attempt with a low profile balloon catheter also failed. In 19 of the 25 patients with successful laser recanalization, the residual stenosis exceeded 50% and was therefore followed by additional balloon angioplasty. The average residual stenosis after laser was 61 +/- 17% of the vessel diameter, and after balloon angioplasty 28 +/- 9% (n = 19), whereas after laser angioplasty alone it was 38 +/- 5% (n = 6). No complications associated with the laser application were observed. Angiographic control after 24 hours showed a reocclusion of 2 (8%) recanalized vessels. In this pilot study, laser angioplasty proved to be a safe and feasible method for the treatment of chronic total coronary occlusions. Because it was necessary to guide the catheter by a central wire, the primary success was limited by a successful passage of the wire of the occlusion. The rate of stand-alone laser angioplasty has to be increased by future improvements of the technique to enable a comparative evaluation of this method with conventional angioplasty.

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.

Prevalence of obstructive sleep apnoea in patients with coronary artery disease.

BACKGROUND: Obstructive sleep apnoea (OSA) is characterized by recurring upper airway collapse with continual respiratory effort during sleep, causing apnoea, a fall in arterial oxygen saturation, arousal and excessive daytime sleepiness. It is a common disorder, with an estimated prevalence of about 1-5% in the adult population. OSA is related to arterial hypertension, an essential risk factor for the development of coronary artery disease (CAD). Furthermore, a high dietary intake is a common risk factor for OSA as well as for CAD. OBJECTIVE: To investigate the prevalence of OSA in CAD patients. METHODS: A random sample of 50 patients (aged 61 +/- 6 years, body mass index 26.8 +/- 3.8 kg/m2) diagnosed to have CAD by coronary angiography was investigated prospectively. Respiration and nocturnal oxygen saturation were registered during one night. Snoring and daytime sleepiness were evaluated by a questionnaire. RESULTS: In 25 patients the apnoea index was > 10/h sleep. Excessive daytime sleepiness was exhibited by eight of these patients. Nineteen of the patients with an apnoea index > 10/h participated in a full night polysomnography. The apnoea index was 17.0 +/- 10.9/h and the apnoea-hypopnoea index was 32.4 +/- 16.5/h sleep. The mean nadir oxygen saturation was 87.3 +/- 1.6% and the minimal oxygen saturation was 75.5 +/- 10.6%. For seven patients the apnoea index was > 20/h. CONCLUSION: CAD patients have a high prevalence of OSA. Since obstructive apnoeas may trigger severe cardiac events such as myocardial ischaemia or ventricular tachycardias in CAD patients, the presence of OSA in these patients should be considered.

Coronary flow analysis during autoperfusion angioplasty.

BACKGROUND: Autoperfusion balloons are available for the protection of the myocardium during balloon angioplasty. The aortic pressure is the driving force that delivers blood to the distal vessel during balloon inflation. Autoperfusion balloons can achieve sufficient flow rates in vitro. The use of these devices is recommended in high-risk patients in danger of haemodynamic collapse during balloon inflation. The quantity of the distal blood flow during balloon inflation in vivo is still unknown. OBJECTIVES: To measure distal coronary perfusion using Doppler guidewires during percutaneous transluminal coronary angioplasty (PTCA) with autoperfusion balloons. METHODS: Coronary flow velocity was measured with 0.014-inch Doppler guidewires bypassing the autoperfusion balloon in eight patients undergoing elective PTCA (degree of stenosis 74 +/- 7.2%). We used balloons with diameters of 3.0 and 3.5 mm. The coronary diameter at the location of the flow measurements was obtained by quantitative angiography in two planes. Coronary blood flow was calculated as the luminal area multiplied by the average peak flow velocity of the Doppler wire divided by 2. Coronary flow velocity reserve was measured before and after angioplasty by intracoronary injection of adenosine. RESULTS: Coronary blood flow was 35 +/- 11.6 ml/min before PTCA. During average inflation times of 4.6 +/- 0.9 min, coronary blood flow was 19 +/- 3.8 ml/min (P = 0.002) after withdrawing the guidewire in the autoperfusion balloon. Five minutes after angioplasty it increased to 42 +/- 13.5 ml/min (P < 0.001). Four patients had electrocardiographic changes during balloon inflation; three patients reported chest pain. One patient required a stent because of a local dissection. To achieve satisfactory angiographic results (residual stenosis 11 +/- 8.5%), we performed 2.1 +/- 0.78 inflations on average with a cumulative inflation time of 8.8 +/- 3.35 min. Coronary flow velocity reserve increased from 1.3 +/- 0.20 to 2.2 +/- 0.22 (P < 0.001). CONCLUSIONS: Using the autoperfusion balloon we measured a coronary blood flow during angioplasty of 56 +/- 10.3% of the distal perfusion before PTCA. In high-risk patients dependent on adequate coronary perfusion, autoperfusion balloons are not able to provide sufficient distal coronary blood flow during balloon inflation. In these patients active coronary or circulatory support devices are recommended.

Clinical parameters associated with collateral development in patients with chronic total coronary occlusion.

OBJECTIVE: Well-developed collaterals provide survival benefit in patients with obstructive coronary artery disease (CAD). Therefore, in this study we sought to determine which clinical variables are associated with arteriogenesis. DESIGN: Clinical and laboratory variables were collected before percutaneous coronary intervention. Multivariate analysis was performed to determine which variables are associated with the collateral flow index (CFI). PATIENTS: Data from 295 chronic total occlusion (CTO) patients (Bern, Switzerland, Amsterdam, the Netherlands and Jena, Germany) were pooled. In earlier studies, patients had varying degrees of stenosis. Therefore, different stages of development of the collaterals were used. In our study, a unique group of patients with CTO was analysed. INTERVENTIONS: Instead of angiography used earlier, we used a more accurate method to determine CFI using intracoronary pressure measurements. CFI was calculated from the occlusive pressure distal of the coronary lesion, the aortic pressure and central venous pressure. RESULTS: The mean CFI was 0.39 ± 0.14. After multivariate analysis, ß blockers, hypertension and angina pectoris duration were positively associated with CFI (B: correlation coefficient ß=0.07, SE=0.03, p=0.02, B=0.040, SE=0.02, p=0.042 and B=0.001, SE=0.000, p=0.02). Furthermore also after multivariate analysis, high serum leucocytes, prior myocardial infarction and high diastolic blood pressure were negatively associated with CFI (B=-0.01, SE=0.005, p=0.03, B=-0.04, SE=0.02, p=0.03 and B=-0.002, SE=0.001, p=0.011). CONCLUSIONS: In this unique cohort, high serum leucocytes and high diastolic blood pressure are associated with poorly developed collaterals. Interestingly, the use of ß blockers is associated with well-developed collaterals, shedding new light on the potential action mode of this drug in patients with CAD.

Detection of coronary microembolisation by Doppler ultrasound during percutaneous coronary interventions.

OBJECTIVE: To validate an intracoronary Doppler ultrasound device for high intensity transient signals (HITS) detection and to assess the incidence of HITS during percutaneous coronary intervention (PCI). METHODS AND RESULTS: In an in vitro model, particle count and number of HITS detected by an intracoronary 0.014 inch Doppler wire were closely correlated (r = 0.97, p < 0.001). In the clinical study, 32 patients (mean (SD) age 61 (11) years; 23 men, nine women) with coronary artery disease were treated with balloon dilatation and stent implantation for a single vessel stenosis. In these patients HITS were detected during PCI in 84% (27 of 32). Reproducibility (r = 0.99, p < 0.001) and interobserver agreement (r = 0.84, p < 0.001) of HITS counts were significant. The number of HITS after stent implantation was significantly higher than after balloon dilatation (11 (7) v 2 (4), p < 0.001). Postprocedural coronary flow velocity reserve (CFVR) was < 2.0 in 55% (16 of 29) of all patients after balloon dilatation and < 2.0 in 23% (six of 26) after stent implantation. The number of HITS after stent implantation did not differ significantly between patients with CFVR < 2.0 and patients with CFVR > or = 2.0 (12 (8) v 10 (7), not significant). CONCLUSIONS: Embolic particles can be detected as HITS by an intracoronary Doppler ultrasound device. Coronary microembolism is often observed during PCI, especially after stent implantation. However, the incidence of HITS alone does not explain a reduced CFVR after PCI.

[Doppler echocardiographic analysis of diastolic function in dilatative cardiomyopathy for the evaluation of its progression and prognosis]. / Dopplerechokardiographische Analyse der diastolischen Funktion bei dilatativer Kardiomyopathie für die Beurteilung von Verlauf und Prognose.

The relationship between left-ventricular diastolic function and the course of the disease was investigated in a prospective study of 61 patients (44 men, 17 women; median age 51 [26-74] years) with dilated cardiomyopathy. The diastolic function was measured by recording the transmitral Doppler flow profile. During a follow-up period of 33 +/- 23 months, 15 patients died (twelve of progressive heart failure, three suddenly without previous heart failure). Cardiac transplantation was performed in four patients. The overall 1-year mortality rate was 14%. A "restrictive" Doppler echocardiographic filling pattern with a steep early-diastolic maximum and a small atrial filling component predominated in the patients who died from progressive heart failure or had a cardiac transplantation because of it. The deceleration of the early diastolic velocity maximum was clearly shorter than in the survivors (111 +/- 32 ms vs 194 +/- 62 ms; P < 0.001). In a Cox proportional hazard model the deceleration time was the best prognosticator, followed by the end diastolic left-ventricular diameter (LVD). The group of patients with a short deceleration time (< or = 140 ms) had a significantly higher 1-year mortality rate (28% [confidence interval 9-47%]) than those in whom it was longer (3% [0-11%]; P < 0.0001). Taking into account LVD it proved possible to identify a prognostically especially unfavourable group with a 1-year mortality rate of 53% (26-80%), characterized by a LVD > 70 mm and a deceleration time < or = 140 ms. Repeated echocardiography in 26 survivors and nine patients who died later or had been operated on showed that the deceleration time did not change significantly in the course of the disease. On the other hand, the systolic function, as measured by the echocardiographically determined shortening fraction, improved in the survivors (from 0.18 +/- 0.07 to 0.22 +/- 0.08; P < 0.05), but not in those who later on died.