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Biomedical subjects

G S Werner

Publications and source records attributed to G S Werner.

At least 19 recordsLinked to original sources
PubMed2006

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.

Acute Disease↗
PubMed2005

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.

Adult↗
PubMed2004

[Mobilization of stem cells by granulocyte colony-stimulating factor for the regeneration of myocardial tissue after myocardial infarction].

BACKGROUND AND OBJECTIVE: Animal data suggest that mobilized bone marrow cells (BMC) may contribute to tissue regeneration after myocardial infarction (MI). However the safety, feasibility and efficacy of treatment with granulocyte colony-stimulating factor (G-CSF) to mobilize BMC after acute myocardial infarction in patients is unknown. We analysed cardiac function and perfusion in 5 patients who were treated with G-CSF in addition to standard therapeutical regimen. METHODS AND RESULTS: 48 h after successful recanalization and stent implantation in 5 patients with acute MI, the patients received 10 micro g/kg bodyweight/day G-CSF subcutaneously for a mean treatment duration of 7.6+/-0.5 days. Peak value of CD34 (+) cells, a multipotent subfraction of bone marrow cells, was reached after 5.0+/-0.7 days. After 3 months of follow-up global left ventricular ejection fraction (determined by radionuclid-ventriculography) increased significantly from 42.2+/-6.6 % to 51.6+/-8.3 % (P<0.05). The wall motion score and the wall perfusion score (determined by ECG gated SPECT) decreased from 13.5+/-3.6 to 9.9+/-3.5 (P<0.05) and from 9.6+/-2.9 to 7.0+/-4.5 (P<0.05), respectively, indicating a significant improvement of myocardial function and perfusion. No severe side effects of G-CSF treatment could be observed. Malignant arrhythmias were not observed either. CONCLUSION: In patients with acute MI, treatment with G-CSF to mobilize BMC appears to be well tolerable under clinical conditions. Improved cardiac function and perfusion may be attributed to BMC-associated promotion of myocardial regeneration and neovascularization.

Adult↗
PubMed2004

Recovery of impaired microvascular function in collateral dependent myocardium after recanalisation of a chronic total coronary occlusion.

OBJECTIVE: To assess the potential for recovery of impaired microvascular function in collateral dependent myocardium after recanalisation of a chronic total coronary occlusion and the determinants of this recovery. PATIENTS AND DESIGN: 120 patients underwent a successful recanalisation of a chronic total coronary occlusion (duration > 2 weeks) and a follow up angiography after a mean (SD) of 5.0 (1.2) months. The coronary flow velocity reserve (CFVR) and the fractional flow reserve were measured after recanalisation and at follow up. Global and regional left ventricular (LV) function were analysed by quantitative angiography. RESULTS: Microvascular dysfunction, defined by a CFVR < 2.0 and a fractional flow reserve > or = 0.75, was observed in 55 (46%) patients after recanalisation. Microvascular function improved during follow up in 24 (20%). The CFVR increased during follow up from 2.01 (0.58) to 2.50 (0.79) (p < 0.001), due to a decrease in basal average peak velocity from 30.7 (14.9) cm/s to 25.5 (13.3) cm/s (p = 0.001). Improved microvascular function was associated with an improved regional LV function, shown by a correlation between increased wall motion severity index and increased CFVR (r = 0.38, p = 0.003). The major determinant of microvascular dysfunction at baseline was the presence of diabetes mellitus (odds ratio 4.3, 95% confidence interval 1.8 to 10.2), which remained so at follow up (odds ratio 4.1, 95% confidence interval 1.3 to 13.4). Improvement of LV function was not impaired by the presence of microvascular dysfunction after recanalisation. CONCLUSIONS: The frequently observed microvascular dysfunction after recanalisation of a chronic total coronary occlusion is a transient phenomenon in most patients and is influenced by the presence of diabetes mellitus. It does not impede the recovery of LV function. Improved regional LV function is associated with improved microvascular function.

Aged↗
PubMed2004

Transarterial aortic valve replacement with a self expanding stent in pigs.

OBJECTIVES: To evaluate the feasibility of percutaneous aortic valve replacement without cardiac arrest in animal experiments. METHODS: A self expanding nitinol stent, containing pulmonary valves from pigs in its proximal part, was implanted in six pigs (94-118 kg) by means of a 25 French catheter through the left subclavian artery under guidance of fluoroscopy and transoesophageal echocardiography. During stent deployment the original aortic valve was pushed against the aortic wall by the self expanding force of the stent while the new valve was expanded. RESULTS: It was possible to replace the aortic valve in the beating heart in four pigs (67%) with no complication or relevant drop in blood pressure. The procedure failed in two pigs (33%) due to dysfunction of the catheter device in one case and to problems with correct positioning in the left ventricular outflow tract in the other. After successful stent valve implantation, dopamine was infused in doses of 5 microg/kg/min, 10 microg/kg/min, and 15 microg/kg/min. Cardiac output increased from 4.4 to 8.8 l/min and the mean arterial pressure rose from 79 to 105 mm Hg. The maximum peak to peak pressure gradient across the valve carrying stent reached a maximum of 8 mm Hg under dopamine infusion. All pigs were killed six hours after transvascular aortic valve replacement. The chest was opened, and the left ventricle and the ascending aorta were carefully inspected. There were no signs of malfunction of the implant, of damage of the aortic vessel wall, or of obstruction of the coronary ostia. CONCLUSIONS: Percutaneous aortic valve replacement with a self expanding nitinol stent in the beating heart is possible. The device was safe under pharmacological stress test. After successful chronic animal experiments, this concept may become a feasible option for treating patients with relevant aortic valve disease but where open heart surgery would be risky.

Animals↗
PubMed2002

[Percutaneous balloon dilatation of discrete subaortic stenosis].

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.

Angiocardiography↗
PubMed2002

[Coronary flow velocity reserve and collateral resistance after recanalization of chronic total coronary occlusions and periprocedural CK and cTNI elevation].

After recanalization and stenting of chronic total coronary occlusions (TCO), a reduced coronary flow velocity reserve (CFVR) and rise in collateral resistance (R(Coll)) is frequently observed. Coronary microembolization may account for these observations. In 86 patients (age 64+/-10 years; 77 men, 9 women) with TCO (duration >4 weeks), PTCA was performed with successful stent implantation in all lesions. Before PTCA, viable myocardium was detected by stress echocardiography or nuclear imaging techniques. By simultaneously measuring coronary Doppler flow velocity and pressure before and after PTCA, CFVR and R(Coll) were calculated. Over a period of 24 hours after intervention, creatine kinase (CK; upper limit of normal [ULN] for women 1.17 micromol/L/s, for men 1.33 micromol/L/s) and cardiac troponin I (cTNI; threshold 0.1 ng/mL) were studied. CFVR was <2 in 48% of all patients. A rise in R(Coll) was observed in 83% of all patients. The incidence of CK and/or cTNI elevation was only observed in 10% of all patients. These patients with CK and/or cTNI elevation did not show a significant difference of CFVR and rise in R(Coll) as compared with patients without CK and cTNI elevation. CFVR or rise in R(Coll) did not correlate with CK elevation. Coronary microembolization is not a likely cause of reduced CFVR and increased R(Coll) after PTCA of TCO. Other factors such as microvascular dysfunction and autoregulatory changes in collateral function may account for these observations.

Aged↗
PubMed2001

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).

Aged↗
PubMed2001

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.

Antioxidants↗
PubMed2001

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.

Aged↗
PubMed2000

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.

Aged↗
PubMed2000

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.

Echocardiography, Transesophageal↗
PubMed1999

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.

Angioplasty, Balloon, Coronary↗
PubMed1999

[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.

Adolescent↗
PubMed1999

[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.

Adult↗
PubMed1999

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.

Aged↗