"False-positive" myocardial perfusion scintigraphy findings in patients with angiographically normal coronary arteries: insights from intravascular sonography studies.

UNLABELLED: Abnormal exercise perfusion findings have been described as false-positive for coronary artery disease in patients with suspected angina and angiographically normal coronary arteries. METHODS: The significance of this finding was further investigated by obtaining intravascular sonograms and Doppler guidewire measurements of at least 2 coronary arteries in 20 consecutive patients who had chest pain, normal coronary angiography findings, and positive stress-rest sestamibi SPECT findings. The summed reversible score was used to describe the extent and severity of reversible perfusion defects. On the basis of scintigraphy findings, vessels were grouped as supplying underperfused myocardial segments (target vessels, n = 20) or normal territories (reference vessels, n = 25). The presence and extension of atherosclerotic disease of the epicardial arteries were assessed by intracoronary sonography. Measurements of plaque area (PA), vessel area (VA), and relative cross-sectional PA (RPA) (RPA = PA/VA) were obtained at the site of maximum plaque concentration. The coronary flow velocity reserve (CFR) was assessed during adenosine-induced hyperemia, and the relative flow reserve was calculated as the target-to-reference coronary reserve ratio. RESULTS: The median summed reversible score was 3 (range, 1-6). Intracoronary sonography showed occult atherosclerosis in 19 patients (95%), with RPA greater than 40% in 16 patients (80%). Mean RPA was significantly greater in the target vessels (46% +/- 14%) than in reference vessels (12% +/- 18%; P < 0.0001). Doppler flow velocity measurements showed abnormal vasodilation capacity (CFR < 2.5) in 14 patients (70%). Mean CFR was significantly lower in the target vessels than in the reference vessels (2.3 +/- 0.5 versus 3.1 +/- 0.6; P < 0.0001). A significant inverse correlation was seen between the summed reversible score and the coronary reserve ratio (y = 9.05x - 9.9; r = 0.70; P < 0.005). CONCLUSION: Reversible perfusion defects seen on SPECT images are often associated with angiographically unrecognized occult atherosclerotic changes and an abnormal vasodilation capacity of the coronary circulation. The tendency to dismiss abnormal exercise perfusion findings as false-positive in these patients may be unjustified.

Diagnostic criteria for detection of postinfarction ischemia by quantitative analysis of stepwise dobutamine radionuclide ventriculography.

BACKGROUND: Application of the traditional diagnostic criteria validated for exercise testing may be inappropriate when dobutamine infusion is associated with radionuclide ventriculography (RNV). The objective of this study was to establish appropriate diagnostic criteria for evaluation of dobutamine stress testing with RNV for the detection of early postinfarction ischemia. METHODS: RNV was performed at baseline and during dobutamine infusion in 10 control subjects and in 30 patients who were studied within 1 week after uncomplicated myocardial infarction. Several quantitative parameters including left ventricular ejection fraction (EF), regional EF, and absolute change in global and regional EF were tested. In addition, regional wall-motion changes were scored by visual analysis. The limit of normal response for each quantitative parameter was defined as the 95th percentile of the distribution observed in control subjects. On the basis of predischarge clinical evaluation and exercise stress testing, patients were grouped as having evidence of residual ischemia (group 1, 15 patients) or no evidence of ischemia (group 2, 15 patients). Sensitivity, specificity, and accuracy in the detection of postinfarction ischemia were calculated for each parameter, and empiric receiver-operating characteristic curves were generated. RESULTS: The limits of the normal response to dobutamine infusion in the control subjects were found to be a 7.5% and a 12.5% increase in global EF at low and high dose, respectively. Median baseline EF was significantly lower in patients than in control subjects (Mann-Whitney U test: P < .001). There were no differences in resting EF between group 1 and group 2 patients. However, median high-dose EF and increase in EF were significantly lower in group 1 as compared with group 2 patients (56% vs 72% and 5% vs 17%, respectively; Mann-Whitney U test: P < .0001 for both). A biphasic (up-and-down) response with initial increase at low dose followed by decrease or no change in EF at high dose was observed in 66% of group 1 patients and only in 13% of group 2 subjects. The best criterion for detection of postinfarction ischemia was a change of <12.5% in global EF at high-dose dobutamine infusion, with 80% predictive accuracy. The traditional criterion, a change of <5 % or a decrease in EF, yielded an accuracy of only 63%. The association of a change of <12.5% with a biphasic response increased accuracy to 87%, with a sensitivity of 93% and a specificity of 80%. Quantitative regional wall motion analysis showed greater diagnostic accuracy than visual wall motion scoring (83% vs 70%). CONCLUSIONS: Application of appropriate criteria and stepwise quantitative analysis of RNV during dobutamine infusion may increase accuracy in the detection of early postinfarction ischemia.

Safety and feasibility of coronary stenting during rescue PTCA: in-hospital outcome.

BACKGROUND: Rescue PTCA is still a debatable procedure and the results published in the literature may not justify routine application of this strategy. AIM: To evaluate the hospital outcome of patients undergoing rescue PTCA with the aim of achieving a complete recanalization of the infarct-related artery (IRA)--residual stenosis assessed with QCA < 30% and TIMI 3 forward flow--obtained with adjuvant coronary stenting when needed. METHOD: From April 1993 to December 1997, 59 consecutive patients underwent rescue PTCA after thrombolysis failure (SK or front-loaded r-tPA, UK) within 6 hours of chest pain onset. All patients had a pre-procedure TIMI 0-1 flow. IRA was the right coronary artery in 23 cases (39%), the left anterior descending in 26 (44%), the left circumflex in 9 (15.3%) and a saphenous vein graft in 1 case (1.7%). In 2 (3.3%) patients, PTCA was not performed (impossibility of crossing the stenosis with the guide-wire). Fifteen patients (26.3%) had a successful procedure (TIMI 3 flow, residual stenosis < 30%) with lone PTCA. Forty-two patients (73.6%) had an intracoronary stent placed (Palmaz-Schatz, Micro-Stent, Multilink, IRIS III): 24 patients (57.1%) for suboptimal angiographic result (TIMI 2 flow, residual stenosis > 30%), 11 patients (26.2%) for dissection, 7 patients (16.7%) for intracoronary thrombosis. All 57 patients had a TIMI 3 flow and a residual stenosis < 30% at the end of the procedure. Mean vessel diameter was 3.22 +/- 0.4 mm, mean balloon size 3.3 +/- 0.4 mm, mean inflation pressure 12 +/- 4 atm, mean residual stenosis 8 +/- 9%. RESULTS: The overall procedure success rate was 96.6%. During hospitalization, three patients (5.1%) suffered subacute reocclusion managed conservatively in one case, with CAGB in another and with re-PTCA in the last one. Three patients (5.1%) had minor vascular complications (groin hematoma) not requiring surgical correction or blood transfusion. No patients died, suffered reinfarction or stroke. All patients were discharged alive and free of angina or clinical heart failure. CONCLUSIONS: Coronary stenting performed in the setting of rescue PTCA leads to a good procedural success rate allowing TIMI 3 flow and low residual stenosis (< 30%). Therefore, when conventional balloon angioplasty is unable to achieve an optimal angiographic result, stenting can be accomplished safely, thereby improving the procedural success rate and allowing a bright event-free survival rate.

Stenting of the Infarct-Related Artery During Complicated Angioplasty in Acute Myocardial Infarction.

The aim of this study was to assess safety and efficacy of coronary stenting as a strategy for improving PTCA suboptimal angiographic result. From March 1993 to December 1995, 104 patients underwent PTCA during acute myocardial infarction. Unplanned coronary stenting was required in 66 pts (63.5%). Procedural success was obtained in 64 pts (97%). Two patients had an unsuccessful stenting procedure: one patient for a suboptimal stent deployment and another for LAD reocclusion requiring emergency CABG (1.5%). Palmaz-Schatz stents were used in 60 pts (91%) and AVE micro-stent in 6 pts (9%). During the hospital course, subacute reocclusion of the vessel occurred in 3 pts (4.6%); one patient underwent a successful rePTCA while the other two underwent CABG. Two patients had vascular groin complications requiring surgical repair of the femoral artery. During hospitalization, one patient underwent elective CABG for early residual myocardial ischemia. At seventy-two hours from PTCA, one patient (1.5%) died as a result of intestinal infarct. Six months survival rate was 98.3% for 59 pts discharged alive from our department. Ten pts were symptomatic during the follow-up: One patient underwent PTCA on another vessel and the other underwent CABG for a multivessel disease. CABG was used in one patient who presented residual silent ischemia in multivessel coronary artery disease. At six months, the first group of patients (18 pts) underwent planned coronary angiography: Vessel patency was present in 17 patients. One patient had an asymptomatic reocclusion of the treated vessel. This study shows a good angiographic result obtained with intracoronary stenting during primary or rescue PTCA of the infarct-related artery. It does not appear to increase major in-hospital adverse events and may reduce the need for surgical revascularization, reducing in-hospital mortality rate and favorably affecting LVEF.

Myocardial uptake of indium-111 antimyosin after coronary angioplasty. Relationship with the total burden of ischaemia.

Indium-111 antimyosin scintigraphy was performed in 24 consecutive patients after percutaneous transluminal coronary angioplasty to assess whether repeated periods of ischaemia during balloon inflation results in myocardial cell damage even after a successful procedure. Patients with unstable angina, prior myocardial infarction and whose procedure was complicated were excluded. Indium-111 monoclonal antimyosin antibodies (80 MBq) were injected 24 h after coronary angioplasty and planar images were collected 24 h later. The relative antimyosin uptake was assessed subjectively and by a heart/lung count density ratio. In addition, the intracardiac gradient of activity was assessed by a count density profile analysis of the cardiac region of interest to distinguish better the focal as opposed to the diffuse antimyosin uptake. The antimyosin uptake index was calculated by multiplying the heart/lung ratio to the intracardiac gradient of activity. After coronary angioplasty, nine patients had minor ST-T wave changes on the surface ECG, but no patient demonstrated a new Q wave. Only three patients showed a mild rise in cardiac enzyme (CK-MB) serum levels. Indium-111 antimyosin uptake (heart/lung > 1.55) was present in eight patients (33%) and was intense (heart/lung > 1.9) in five (21%). Antimyosin uptake was always seen in myocardial segments corresponding to the treated coronary artery. Patients with a positive antimyosin scan had a longer duration of balloon-induced ischaemia compared with patients with no evidence of antimyosin uptake (541 +/- 211 vs 331 +/- 137 s, P < 0.007).(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial dissection following successful chemical ablation of ventricular tachycardia.

We describe a case of fatal myocardial rupture and tamponade following a successful transcoronary chemical ablation of incessant ventricular tachycardia. Pathological examination showed a subepicardial dissection of the heart at the ablation site with fibrous and fatty degeneration of the myocardium. The present report calls for caution, underlying a possible lethal complication of ethanol ablation which has not been described before.

Iopamidol in cardioangiography: a retrospective, multicenter study. Part I. Adult patients.

To evaluate the occurrence of complications during diagnostic or interventional catheterization a retrospective analysis of catheterization procedures in 12 Italian laboratories using the nonionic contrast medium (CM) iopamidol (370 mgI/ml) was performed. Data obtained on 26,219 patients greater than or equal to 14 years are presented. The overall complication rate was 1.89% (485/26,219). The overall mortality rate was 0.1% (27/26,219). Procedure related complications were 389 (1.48%) and CM related complications were 106 (0.4%). No death was attributed to CM. Ventricular fibrillation (VF) rate was 0.11% comparable to the low rate observed with nonionic CM in other studies and less than the rate observed in surveys concerning the use of ionic CM. Fifty-seven thrombotic events were recorded (0.22%), a rate comparable with other surveys with ionic and nonionic CM. The total complication rate (6.1%), the rates of coronary occlusion (1.34%), myocardial infarction (0.37%) and urgent coronary artery by-pass grafting (0.5%) in 1,348 coronary angioplasties were lower than those recorded in previous surveys. These data confirm a good tolerability and no increased risk of VF and thrombotic events with iopamidol in cardiac catheterization.

Iopamidol in cardioangiography: a retrospective, multicentre study. Part II. Paediatric patients.

To evaluate the complication rate in paediatric cardioangiography with the nonionic contrast medium iopamidol data on 8,166 procedures were retrospectively collected in 12 centres. The overall complication rate was 3.78% (309/8,166). 3.44% were related to the procedure, and 0.34% to the contrast medium. The mortality rate varied with age. It was higher in patients less than 2 months (0.38%) than in patients greater than 2 months-2 years (0.06%) and in patients older than 2 years (0.03%). The total complication rate was higher than the one observed in a similar retrospective analysis performed in adult patients (1.89%). This difference is probably due to higher risk conditions of the younger patients. However the contrast medium related complication rate (0.34% vs 0.4%) and the mortality rate (0.11% vs 0.1%) were comparable, confirming the good tolerability of iopamidol in cardiac catheterisation also in paediatric patients.

[Percutaneous mitral commissurotomy: immediate and short-term results]. / Commissurolisi mitralica percutanea: risultati immediati e a breve termine.

31 symptomatic patients with mitral stenosis were selected for percutaneous transvenous mitral commissurotomy using Inoue catheter. The patients were selected using the echocardiographic score for: leaflets mobility, leaflets thickening, subvalvular thickening, degree of calcifications. All patients had a score less than or equal to 8 and represented 17.5% of the patients studied in our echocardiographic laboratory for mitral stenosis. We were able to perform the commissurotomy in 30 of them. Mean left atrial pressure decreased from 26 +/- 5.2 mmHg to 14.6 +/- 6 mmHg (p less than 0.001). The mean mitral diastolic pressure gradient decreased from 8.9 +/- 3.1 mmHg to 3.9 +/- 1.3 mmHg (p less than 0.001). The mitral valve area, using the echocardiographic Pressure Half Time (PHT), increased from 0.94 +/- 0.17 cmq to 1.96 +/- 0.33 cmq (p less than 0.001). Mitral regurgitation, angiographically evaluated in 29 patients, increased in 11 (38%), being of degree + + + in 3 patients. There were 2 heart tamponades and 5 cases (16.6%) of left-to-right shunt with Qp / Qs less than 2. After 3 months, the follow-up showed improvement of one or more functional classes in 96.6% of all patients. The mitral valve area, determined after 6 months in 24 patients by PHT, was stable (1.98 +/- 0.31 vs 1.93 +/- 0.25) (p = 0.5); we did not find mitral stenosis recurrence in any instance. In the first 10 patients, after 1 year, the results are stable (1.85 +/- 0.28 cmq vs 1.93 +/- 0.21 cmq) (p = 0.5) without mitral stenosis recurrence. These data suggest that in selected tight mitral stenosis the percutaneous transvenous commissurotomy may be alternative to the open surgical solution. Using an Inoue catheter, the percutaneous transvenous mitral commissurotomy is easier and the complications are few. The major procedural hazards derive from the transseptal technique.

Reliability of standard apexcardiography for the measurement of sudden variations in mean pulmonary capillary wedge pressure.

We simultaneously registered the left apexcardiogram together with the left intraventricular pressure curve immediately before and after ventricular angiography in order to evaluate whether the relation existing between apexcardiographic protodiastolic filling period duration (cR interval) and left ventricular mean diastolic pressure (LVMDP) was maintained even in the presence of sudden variations of LVMDP. Administration of contrast media resulted in a significant increase of LVMDP (from 11.8 to 23.9 mm Hg) and in a simultaneous decrease of the cR interval (from 108.5 to 71.0 msec) and noninvasive LVMDP calculated as 36-0.24* cR closely correlated with the invasive values both before and after angiography (overall correlation r = 0.94). Apexcardiography thus confirms to be the only highly reliable noninvasive technique which can be used by the clinical cardiologist to measure LVMDP and/or mean pulmonary capillary wedge pressure.

Management of complicated coronary angioplasty by intracoronary urokinase and immediate re-angioplasty.

Percutaneous transluminal coronary angioplasty was complicated by acute coronary occlusion, dissection of the arterial wall, or angiographic evidence of intraluminal thrombosis in 33 high-risk patients from 153 consecutive angioplasty procedures (21.5%). Ten patients (group I) were managed with nitroglycerin (0.2 to 0.4 mg i.c.) and repeated attempts at mechanical guide wire recanalization or dilation, but they did not receive thrombolytic therapy. In the remaining 23 patients (group II), intracoronary urokinase (100,000 to 360,000 U.I.) was administered over 15-20 min after onset of coronary occlusion or thrombosis and continued during attempts at repeated dilation of the stenosis. The incidence of sudden coronary artery occlusion was 70% in group I patients and 52% in group II. The angiographic evidence of thrombus formation was observed in a higher, but not significant, proportion of group II patients (65%) as compared with group I (30%). The incidence of intimal tearing or dissection was similar in the two groups of patients (40 vs. 34.7%). The overall final success rate of the complicated angioplasty series was 48% (6/33). However, the success rate was lower (10%) in group I than in group II patients (10 vs. 65%; P less than 0.005), and the frequency of emergency coronary artery bypass grafting was lower in group II patients (13 vs. 60%; P = 0.01), suggesting that thrombolytic therapy with urokinase may be effective in the management of acute coronary occlusion and thromboembolic complications of coronary angioplasty.

Emergency coronary angioplasty in patients with severe left ventricular dysfunction or cardiogenic shock after acute myocardial infarction.

Emergency percutaneous transluminal coronary angioplasty (PTCA) was performed during an acute myocardial infarction (AMI) after either systemic or intracoronary thrombolytic therapy in six patients with severe ischaemic left ventricular dysfunction or cardiogenic shock, among 37 patients (17%) who were treated with PTCA during AMI over a 13-month period. Thrombolytic therapy with streptokinase (1.5 x 10 Units) was initiated after a mean (+/- SD) time delay of 5.5 +/- 1.3 h from the onset of symptoms. The infarct-related artery was found to be occluded (TIMI grade 0-1) in three patients and partially reperfused (TIMI grade 2) in the remaining patients at baseline coronary angiography. Intracoronary administration of urokinase (100-200,000 Units) was ineffective in those patients failing systemic thrombolysis and resulted in only a slight increase of residual lumen in three patients. The coronary artery could be opened by a guidewire mechanical technique in patients with persistent coronary artery occlusion and coronary dilation could be done in all patients. The mean percentage diameter stenosis of the infarct-related vessel was reduced from 98.8 +/- 2% to 27 +/- 11% (P less than 0.005). After the procedure, left ventricular ejection fraction increased from 27 +/- 8% to 41 +/- 7% (P less than 0.02), systemic blood pressure and cardiac index increased respectively from 86 +/- 10 to 126 +/- 14 mmHg (P less than 0.005) and from 2.2 +/- 0.6 to 3.3 +/- 0.6 (P less than 0.01). Left ventricular end-diastolic pressure decreased from 26 +/- 8 to 18 +/- 3 mmHg (P less than 0.05). Severe mitral regurgitation was relieved in one patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspergillus flavus-infection of a pacemaker wire: continuing evidence for active management of infected pacemakers.

A rare case of fungal endocarditis (Aspergillus flavus) on a permanent pacemaker is described. Owing to negative blood culture and non-specific echocardiographic findings, a complete diagnosis was made only on histologic examination of the surgically removed material. In our opinion this case supports an active management of infected pacemakers.

[The Italian Group for the Study of Streptokinase in Myocardial Infarct: Coronarographic and ventriculographic study]. / G.I.S.S.I.: Studio coronarografico e ventricolografico.

The effects of intravenous thrombolytic treatment on the reperfusion of infarct related coronary artery and left ventricular function were assessed in 251 pts. with first episode of myocardial infarction, enrolled in the G.I.S.S.I. trial, in which coronary angiography and left ventriculography have been performed within the second and third week from the onset of symptoms. A total of 251 pts. were randomized in two groups--133 treated with streptokinase (SK) and 118 controls. Among those treated with SK, in 71 (57.9%) the treatment was started within 3 hours and in 56 (42.1%) after 3 hours from the onset of symptoms. The infarct related vessel was occluded in 43 (32.3%) patients treated and in 60 (50.9%) controls (p less than 0.01). No significant difference was found in the left ventricular ejection fraction among the treated patients and controls while a significant difference resulted in the percentage of patients who had left ventricular ejection fraction greater than or equal to 50% in the group of patients with SK within 3 hours in comparison to controls. Left ventricular ejection fraction remained normal without any correlation with the type and time of the treatment, if the infarct related vessel resulted open at the coronary angiography. The study of the regional wall motion of left ventricle did not show any significant difference neither in the infarct size nor in the type and the time of treatment. In conclusion, the thrombolitic treatment with SK in acute myocardial infarction using the protocol adopted in the G.I.S.S.I. trial, obtains the reopening of infarct related vessel in an high percentage of patients; this event helps in great measure to conserve left ventricular function, especially in patients with anterior myocardial infarction if the treatment was started within the first 3 hours from the onset of symptoms.

[The internal mammary artery in myocardial revascularization]. / L'arteria mammaria interna nella rivascolarizzazione miocardica.

Internal mammary artery by-pass graft is a very usefull alternative to venous by-pass graft for myocardial revascularization. From February 1982 up to August 1984, 111 patients with coronarosclerosis have been operated on with left internal mammary artery. Right internal mammary artery has been also used in 2 cases. Left internal mammary artery has been used as a sequential graft 13 times. Vein grafts have been associated in more than 2/3 of the patients who had surgery with internal mammary artery and the mean of anastomoses per patient was 2.9. Five patients had a perioperative myocardial infarction and one an infarction shortly after the operation. Ten patients had immediate reoperation: 5 for postoperative bleeding, 2 for arterial graft anastomosis occlusion, 2 for sudden ST elevation and 1 for acute myocardial infarction. Only one patient died for acute myocardial infarction post-operatively, following coronary artery spasm. Eighty-six patients have been followed-up 3 to 31 months after surgery. Advantages and limits of this surgical technique are discussed.

[Angioplasty of the common trunk of the left coronary artery with venous patch]. / Angioplastica del tronco comune della coronaria sinistra con patch venoso.

Surgical angioplasty of the left main coronary artery for severe iatrogenic stenosis has been done on a 40 year old female patient operated upon five months before for mitral and aortic valve prosthetic replacement. Postoperative angiocardiographic study showed patent left main trunk and the patient is angina-free six months post-operatively. Operative indication and surgical technique are discussed as an alternative to aorto-coronary by-pass surgery for left main proximal stenosis without peripheral lesions. It does not result from literature that this surgical technique has ever been employed in patients previously operated with open heart surgery.

[Phase and amplitude images using Fourier analysis in radioisotopic angiography. Comparison with contrast angiography for studying regional changes in ventricular contraction]. / Immagini di fase e ampiezza mediante analisi di Fourier in angiografia radioisotopica. Confronto con l'angiografia di contrasto per lo studio delle alterazioni regionali della contrazione ventricolare.

Phase-amplitude images and phase distribution histograms, derived from a temporal Fourier analysis of equilibrium ecg-gated blood pool studies, were used to assess the overall wall motion synchronism and to detect regional wall motion abnormalities in 69 consecutive patients with suspected or documented coronary artery disease, in whom biplane contrast left ventriculography and coronary angiography were performed. Four regions were considered on the 15 degrees caudal left-anterior oblique view radionuclide image, in order to identify the 7 conventional angiographic left ventricular wall segments (as the American Heart Association Council of Cardiovascular Surgery). Regional abnormalities on the phase-amplitude images from the 15 degrees caudal left anterior oblique view scans were studied in order to identify local hypokinesis, akinesis or dyskinesis (in accord to definitions used for contrast cineangiography) relative to seven conventional left ventricular wall segments. Results of phase-amplitude image analysis were compared with those of contrast cineangiography. The parametric images showed overall sensitivity of 82% and 92% respectively towards biplane and monoplane (left anterior oblique) contrast cineangiography, with a high degree of specificity (97%). Most akinetic and dyskinetic segments were correctly identified. A significant phase delay (greater than or equal to 70 degrees) from mean value, always occurred in dyskinetic segments and generally related to the severity of the wall motion abnormality. Lower accuracy was observed for hypokinetic regions; sensitivity was lower for apical and antero-lateral segments.(ABSTRACT TRUNCATED AT 250 WORDS)

Transluminal extraction of a catheter fragment from the aortic arch.

Many different techniques have been previously reported for non-surgical transluminal removal of foreign bodies from venous system or right heart chambers, while only few cases of transluminal extraction from arterial vascular bed or left heart chambers have been published. We report a successful attempt of a Judkins' catheter fragment extraction from the aortic arch by a homemade loop-snare device. Tying the distal end of a long flexible guide-wire on the tip of a 8F Cournand catheter we obtained an easy to handle device which is practicable using instruments always available in any catheterization room.