Biomedical subjects
Publications and source records attributed to M Zimarino.
Coronary lumen changes after excimer laser coronary angioplasty, after adjunct percutaneous transluminal coronary angioplasty, and at 24 hours after intervention were assessed using quantitative coronary angiography. Lesions treated with this combined technique showed significant early deterioration within 24 hours.
To evaluate the mechanisms of lumen enlargement and the respective contributions of rotational coronary atherectomy (RA) and adjunctive percutaneous transluminal coronary balloon angioplasty (PTCA), serial measurements were recorded in 70 consecutive patients by quantitative coronary angiography before RA, after RA, after adjunctive PTCA, and 24 hours later. Minimal luminal diameter (MLD) increased from 0.85 +/- 0.31 mm to 1.42 +/- 0.27 mm (p < 0.001) after RA and to 2.20 +/- 0.46 mm (p < 0.001) after PTCA. Minimal luminal area (MLA) increased from 0.64 +/- 0.50 mm2 to 1.63 +/- 0.60 mm2 (p < 0.001) after RA and to 3.97 +/- 1.68 mm2 (p < 0.001) after PTCA. Both 24-hour MLD and MLA showed a trend toward reduced values (2.07 +/- 0.45 mm and 3.52 +/- 1.70 mm2, respectively) when compared with immediate results after PTCA. The absolute gains in MLD after RA and after PTCA were 0.56 +/- 0.24 mm and 0.79 +/- 0.38 mm, respectively (p < 0.01). The absolute gains in MLA after RA and after PTCA were 0.99 +/- 0.49 mm2 and 2.34 +/- 1.41 mm2, respectively (p < 0.001). The respective contributions of RA and PTCA are highly variable, but in general, balloon dilatation accounts for most of the gain in lumen area and therefore is not an adjunctive but a primary technique.
BACKGROUND: Minimally invasive coronary artery bypass grafting has recently been introduced into cardiac surgery. In this report we discuss the incidence of surgically induced distal target vessel stenosis in patients who undergo the minimally invasive coronary artery bypass grafting procedure, which represents a major drawback of the procedure in our experience. METHODS: Doppler evaluation of mammary artery flow was performed postoperatively in all 55 patients who underwent minimally invasive coronary artery bypass grafting at our institution. Angiography was performed in the first 35 consecutive patients for control purposes and in 2 patients who complained of angina recurrence. RESULTS: In 32 of the first 35 consecutive patients, the anastomosis was found to be functioning normally and the distal left anterior descending artery was normal; in the remaining 3 patients we found mammary artery occlusion, anastomotic stenosis, and stenosis of the anastomosis and the distal left anterior descending artery in 1 patient each. A distal left anterior descending artery stenosis was found in the only 2 patients who underwent late angiography. CONCLUSIONS: Surgically induced distal target vessel stenosis represents a major drawback of minimally invasive coronary artery bypass grafting in our experience. Further improvement in the means of achieving coronary artery occlusion, as well as in anticoagulant and antiplatelet therapy, is mandatory before minimally invasive coronary artery bypass grafting can be confidently accepted into clinical practice.
AIM OF THE STUDY: Minimally invasive direct coronary artery by-pass (MIDCAB) has been proposed as an alternative technical solution in different clinical settings. However, a systematic angiographic study of the results obtained using this new technique has not been published yet. This paper summarizes our preliminary angiographic results with MIDCAB. MATERIALS AND METHODS: From January 1995 to January 1997, 56 patients underwent MIDCAB. All patients were followed up regularly and underwent stress myocardial scintigraphy. A postoperative angiographic control was performed in 48 patients (87.2% of the total) at a mean postoperative interval of 1.7 +/- 2 months. RESULTS: One patient died in hospital. Five patients required further surgery using conventional techniques (either surgical or percutaneous). In 41/48 patients (85.4%), the mammary artery graft and the left anterior descending artery (LAD) were normal. In two cases, we found an anastomotic stenosis, in two cases there was a LAD lesion distal to the anastomosis (at the application site of the stay sutures), one case showed an anastomotic stenosis associated with a distal LAD stenosis, one case had a mammary graft occlusion and one case showed a thrombus-like image in the LAD proximal to the anastomosis. CONCLUSION: Systematic angiographic follow-up of MIDCAB patients seems mandatory in order to evaluate the effectiveness of the technical solutions utilized and to optimize various aspects of this new procedure.
Stent deployment in a lesion with a large side branch is an example of the potential limitation of intracoronary stents, especially the Palmaz-Schatzª stent with its tubular slotted design. This case study describes a patient in whom a Palmaz-Schatz stent of excessive length covered the origin of a side branch (Òstent jailÓ). Thrombus developed in the jailed branch as well as in the main vessel, causing abrupt vessel closure and impending acute myocardial infarction within one hour after the procedure. This complication was successfully managed by emergency repeat angioplasty and implantation of a Micro Stentª on both branches, i.e. in the main vessel distal to the Palmaz-Schatz stent and in the side branch through the struts of the Palmaz-Schatz stent.
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UNLABELLED: Coronary angioplasty is an effective method to achieve myocardial reperfusion in acute myocardial infarction (AMI). We reviewed our experience in 132 patients (pts) who underwent percutaneous transluminal coronary angioplasty (PTCA) of a totally occluded infarct-related artery (IRA) within 24 h after the onset of symptoms (mean delay 10 +/- 7 h), in order to identify the predictors of primary success and of major complications. PTCA was successfully performed in 113 patients (86%). Failure without complications occurred in 12 patients (8.4%); untoward events (death and emergency CABG) occurred in seven patients (5.3%). Pts in the failure group were more likely to have cardiogenic shock (53 vs. 8.8%, P < .0005), longer time to reperfusion (15 +/- 6 vs. 9 +/- 6 h, P < .0005), lower ejection fraction (EF) (42 +/- 16 vs. 54 +/- 12%, P < .0005), multivessel disease (74 vs. 43%, P < .03), and a smaller IRA diameter (2.8 +/- 0.6 vs. 3.1 +/- 0.6 mm, P < .03). Sex, age, previous bypass surgery, previous thrombolytic treatment, IRA, and infarct location were similar in both groups. Absence of cardiogenic shock (P < .0001), decreasing time to reperfusion (P < .005) and increasing EF (P < .02) were independent predictors of successful PTCA. Presence of cardiogenic shock (P < .0001) and decreasing EF (< .05) were independent predictors of untoward events. Repeat angiography was performed 24 h after the procedure in the success group. Angiographic deterioration (stenosis > or = 50% and/or TIMI flow grade < or = 1) was present in 18 pts (16%), among whose 5 pts (4.4%) had re-occlusion of the IRA. Pts with early angiographic deterioration were more likely to have a lower IRA diameter (2.8 +/- 0.5 vs. 3.1 +/- 0.6 mm, P < .02). CONCLUSION: Emergency PTCA is an effective method for establishing reperfusion in AMI. Pts with high-risk baseline characteristics show the highest rate of untoward events, but are the most likely to benefit from aggressive reperfusion therapy.
Nicorandil is a compound with hybrid properties of nitrates and adenosine triphosphate (ATP)-sensitive potassium channel (KATP) opening. The effects of nicorandil and isosorbide dinitrate (ISDN) were investigated in a model of 60-min coronary occlusion/180-min reperfusion in open chest pigs. Three groups of 10 pigs were randomly assessed to receive saline or equihypotensive doses of nicorandil or ISDN. Drug infusion was started at 30 min of ischemia and continued throughout reperfusion. Area at risk (AAR) and infarcted area (IA) were assessed by monastral blue dye-triphenyltetrazolium dual staining technique and calculated by planimetry. Myeloperoxidase concentration (MPO) in the non-ischemic area and in the IA was assessed as an index of presence of neutrophils. Measurements of reduced glutathione (GSH), oxidized glutathione (GSSG), lipofuscine, and malondialdehyde were performed on coronary vein blood as indexes of oxidative stress. IA, as a percentage of AAR, was 78 +/- 10% after saline, 61 +/- 12% after N (p < 0.05 vs. saline), and 69 +/- 14% after ISDN (not significant vs. saline). Cardiac output and left ventricular dP/dt were depressed during coronary occlusion in all groups and their recovery during reperfusion was earlier in the nicorandil group. In the saline group, MPO was increased in the IA compared to the nonischemic area (78 +/- 63 vs. 21 +/- 21 micrograms/mg prot, p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
BACKGROUND: Percutaneous coronary angioplasty (PTCA) is an effective method to achieve myocardial reperfusion in acute myocardial infarction. In order to identify the predictors of primary success and major complications, we reviewed our experience in 107 patients (pts) who underwent PTCA of a totally occluded infarct-related coronary artery (IRA) within 24 hours (h) after the onset of symptoms. METHODS AND RESULTS: PTCA was successful in 92 pts (86%); PTCA failed without complications in 9 pts (8.4%), major complication (death and urgent coronary artery surgery) occurred in 6 pts (5.6%). Rescue PTCA was performed in 31% of cases and had similar success rate when compared to direct PTCA (85 vs 86%, p = NS). Pts with successful PTCA had repeat angiography 24 h after the procedure. According to primary and 24 h results, pts were divided into 3 groups: primary success with 24 h stable result (Group A: 76 pts, 71%); primary success with 24 h deterioration (Group B: 16 pts, 15%), among which 4 pts showed total reocclusion; primary failure (Group C: 15 pts, 14%). A longer time delay from symptoms onset (p < 0.05), cardiogenic shock (p < 0.001), previous bypass surgery (p < 0.05) were correlated with worse short-term outcome by univariate analysis. When compared to Group A, pts in Group C showed a lower EF (42 +/- 14 vs 51 +/- 16%, p < 0.05). IRA diameter was greater in Group A (3.1 +/- 0.4 mm) when compared to Group B (2.7 +/- 0.4 mm, p < 0.05) and Group C (2.7 +/- 0.5 mm, p < 0.05). Absence of cardiogenic shock (p < 0.001), decreasing time from symptoms onset (p < 0.01) and increasing ejection fraction (EF) (p < 0.05) were independent predictors of primary success by multivariate analysis. Cardiogenic shock (p < 0.001) and decreasing EF (p < 0.05) were independent predictors of major complications. CONCLUSIONS: PTCA of IRA is effective within 24 h from symptoms onset. Procedural failure is infrequent, usually occurring in patients with high-risk baseline characteristics.
Pulmonary capillary wedge pressure, currently accepted as an approximation of left atrial pressure, leads to underestimation of mitral valve area calculated with the Gorlin formula. Wave delay has been pointed out as a major source of the underestimation. The aim of this study was to increase the accuracy of pulmonary artery wedge pressure-based measurements through a correction for time delay. Electrocardiogram, pulmonary capillary wedge, left atrial and left ventricular pressures were recorded simultaneously at high paper speed in 18 patients with mitral stenosis who underwent transseptal left atrial catheterization prior to mitral valvulotomy. Heart rate and wedge pressure wave delay were closely correlated (r = 0.78, p < 0.001). Linear regression equation (y = 1.1x + 8) was then applied in order to adjust the pulmonary capillary wedge pressure for time delay in every complex. Relative to mitral area measured with left atrial pressure, areas calculated using wedge pressure with and without correction were, respectively, 5 +/- 6% and 16 +/- 7% (p < 0.001) lower. Both methods showed a close correlation (r > 0.95) with measurements obtained using left atrial pressure; plotting the standard deviation against the mean, the correction of capillary wedge pressure significantly (p < 0.001) increased the accuracy of area measurement. In conclusion, pulmonary wedge pressure, properly obtained and adjusted for time delay, allows a more reliable measurement of the mitral area.
We report the case of a 58-year-old woman who underwent outpatient coronary angiography with 5F catheters for atypical chest pain. Superselective angiography of a right superior septal artery mimicked a coronary arteriovenous fistula. Appropriate placement of the catheter in the ostium of the right coronary artery excluded the suspected anomaly.
Several new techniques have been developed to get round the limitations of conventional coronary angioplasty. Most entail ablation of the atheromatous plaques by mechanical (atherectomy) or photochemical (laser excimer) means, whilst others (stents) shore up the vascular walls. Their use with conventional coronary balloon angioplasty optimises the results of treatment of complex lesions. This report describes the authors' experience in 1,266 patients (1,668 lesions) treated between January 1992 to December 1993. The new techniques were used in 33% of patients and 30% of lesions (rotational) atherectomy: 20%; stents: 5%; directional atherectomy: 3%; laser excimer: 2%) because of the defavourable angiographic characteristics of the lesions (eccentricity, calcification, bifurcation, length, chronic total occlusion, thrombosis, ostial stenosis, ulceration, saphenous vein graft). The primary success rate was 91% in the whole group (94 to 97% for the patients treated by the new techniques). The global major complication rate was 1.7%. The multi-instrumental revascularization adjusted to the coronary lesions (MIRACLE) gives a high primary success rate in patients with coronary lesions difficult to treat by conventional angioplasty. Randomised trials will be necessary to determine the precise indications of each technique with respect to the morphological characteristics of each lesion.
Conventional balloon angioplasty (PTCA) of ostial lesions (OL) is associated with suboptimal results and a higher complication rate. Partial plaque ablation with rotational atherectomy (RA) before PTCA might improve results. This approach was used in 63 patients (pts) (mean age 64 +/- 10 yrs; 44 men, 19 women) with 69 OL. There were 15 aorto-OL and 54 branch-OL. Calcification was more frequent in aorto-OL than in branch-OL (67% vs. 35%, P < 0.05). Mean burr size was 1.8 +/- 0.3 mm. Burr-artery ratio was 0.74 +/- 0.10. Adjunctive PTCA was systematically performed. Procedural success was achieved in 58 pts (92%): 14 aorto-OL (93%) and 50 branch-OL (93%) were successfully treated; major complications occurred in 1 (7%) aorto-OL and 1 (2%) branch-OL. Uncomplicated failure occurred in three cases. Minimal lumen diameter (MLD) increased from 0.69 +/- 0.31 mm before RA to 1.43 +/- 0.28 mm after RA (P < 0.001) and 2.16 +/- 0.29 mm after PTCA (P < 0.001). Diameter stenosis (DS) decreased from 75 +/- 13% before RA to 32 +/- 12% after RA (P < 0.001) and 14 +/- 10% after PTCA (P < 0.001). All successfully treated pts underwent repeat angiography 24 h later and exercise testing or repeat cardiac catheterization > 6 mo later. At 24 h repeat angiography, DS was 17 +/- 15% (P = NS vs. after PTCA); no lesion had a DS > or = 50%. Follow-up coronary angiography was performed in 30 pts (52%) who had abnormal stress testing: 13 pts (43%) showed angiographic restenosis in at least one successfully treated OL. (ABSTRACT TRUNCATED AT 250 WORDS)
One of the causes for percutaneous transluminal coronary angioplasty (PTCA) failure is the inability to cross the lesion with the balloon catheter after guidewire positioning. The Europass coronary angioplasty catheter is a monorail Duralyn balloon catheter developed to enhance lesion crossability and to overcome this limitation. This system was evaluated in 50 patients in which target lesions were chronic total coronary occlusions (12 cases) or stenoses that could not be reached or crossed by other new monorail balloon catheters. Overall procedural success was obtained in 49/50 patients (98%), using a single Europass balloon catheter in 46/50 patients (92%), with no in-hospital complications. Its low profile, small distal shaft, and excellent trackability allowed successful angioplasty in cases where other catheters failed. This balloon catheter represents a significant advance in angioplasty technology and can be considered as a first-choice device for a safe and expeditious single-operator procedure.
In the treatment of branch-ostial lesions (BOL) balloon angioplasty (PTCA) is associated with suboptimal results and a higher complication rate. Rotational atherectomy (RA) before PTCA might improve results. This approach was used in 37 patients (mean age 62 +/- 10 years; 27 men, 10 women) with 42 BOL. Mean burr size was 1.7 +/- 0.3 mm; burr-artery ratio was 0.75 +/- 0.10. Procedural success was achieved in 39 (93%) BOL; the only major complication was a periprocedural myocardial infarction (CPKMB=58IU/ml). In 2 cases the stenosis was not crossed by the guidewire. Diameter stenosis (DS) decreased from 72 +/- 14% before RA to 30 +/- 12% after RA (p < 0.001) and 15 +/- 10% after PTCA (p < 0.001). All patients with a successful procedure underwent repeat angiography 24 hours DS was 18 +/- 15 (NS versus after PTCA); no lesion had DS > or = 50%. RA with adjunctive PTCA is a safe and effective treatment of BOL, with short-term stable results.
The analysis of valvular morphology is important in selecting patients with mitral rheumatic stenosis for percutaneous mitral valvuloplasty. Transthoracic echocardiography definitely plays a major role in this characterization whereas the usefulness of transesophageal echocardiography has not been determined yet. We studied 95 patients (82 females, 13 males, mean age 51 +/- 12 years) undergoing mitral valvuloplasty (Inoue's technique). The two methods were compared for: morphologic mitral score; correlation between score and increase in mitral valve area; ability to predict post valvuloplasty mitral regurgitation; accuracy in detecting atrial thrombosis. A significant linear correlation between transthoracic and transesophageal echocardiographic scores was observed (r = 0.78, p < 0.001). Transesophageal echocardiographic score was significantly lower (6.8 +/- 1.62 versus 7.17 +/- 1.69, p < 0.05) due to a lower estimation of the extent of calcifications (0.7 +/- 0.97 versus 1 +/- 1.12, p < 0.05). Correlation coefficients between increase in mitral valve area and scores obtained with the two methods were similar (0.29 and 0.30). For both echocardiographic techniques 6 was the best cut-off score value. None of the clinical, hemodynamic and echocardiographic variables was able to predict the occurrence of severe mitral regurgitation. Five patients with atrial thrombosis were identified by transesophageal echocardiography but only 1 by transthoracic echocardiography. We conclude that the two echocardiographic methods have complementary roles in the evaluation of patients undergoing mitral balloon valvuloplasty. Mitral valve morphologic score can generally be assessed adequately by transthoracic echocardiography but transesophageal echocardiography is mandatory in order to exclude left atrial thrombi. The occurrence of post valvuloplasty severe mitral regurgitation cannot be reasonably predicted on echocardiographic basis.
Rotational coronary atherectomy with adjunctive balloon angioplasty was performed in 36 patients older than 70 years. Previous myocardial infarction, coronary angioplasty and coronary artery bypass were present in 44%, 11% and 14%, respectively. Thirty-six percent and 33% of patients presented stable and unstable angina pectoris, respectively. Totally, 46 lesions were treated (1,3 lesion/patient). All lesions had complex morphology characteristics: eccentricity (63%), calcification (69%), angulation (44%), length > 10 mm (11%), undilatable rigid lesion with failed PTCA (11%), ostial disease (9%), ulceration (7%). In 39% was present a single-vessel disease, in 44% double-vessel disease and in 17% triple-vessel disease. Five patients received rotational atherectomy on two stenoses in the same vessel, 5 received a two vessels treatment. Procedure was successful in 94% of patients; 2 patients (6%) had major complication (1 urgent coronary artery bypass and 1 acute myocardial infarction) without any death. All patients with successful rotational atherectomy had repeated coronary angiography at 24 hours. No patient showed significant deterioration (stenosis > or = 50%) of the initial result at 24 hours. Rotational atherectomy can be performed in patients over 70 years with complex coronary lesions with a high success rate, low complications and persistence at 24 hours of initial gain. It should be considered as a primary therapeutical option in selected cases with complex coronary lesions in which conventional PTCA can be unsuccessful.
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