Restenosis and progression of coronary disease after balloon angioplasty in patients with diabetes mellitus.

BACKGROUND: Patients with diabetes mellitus (D) (both insulin-requiring D [IRD] and non-IRD) who undergo angioplasty have worse long-term outcome than do non-D patients. Few data are available in the literature that explain these findings. HYPOTHESIS: The study was undertaken to compare restenosis and progression of coronary disease after angioplasty in IRD patients, in non-IRD patients, and in non-D patients. METHODS: Diabetic patients who underwent coronary angioplasty were separated into two subgroups: IRD and non-IRD patients. Their angiographic outcome was compared with non-D patients. We examined retrospectively 353 coronary angiograms of patients who were referred for diagnostic angiography > 1 month after successful angioplasty. Quantitative angiography was used to determine the outcome in dilated narrowings (restenosis) and in nondilated narrowings (disease progression). RESULTS: Baseline clinical and angiographic characteristics were similar in all groups. Restenosis rate was higher in IRD (61%) than in non-IRD (36%) and non-D (35%) patients (p = 0.04). Late luminal loss after angioplasty was two times greater in IRD patients than in the other two groups (p = 0.01). Disease progression of nondilated narrowings was significantly more prominent in non-IRD than in non-D patients: Diameter stenoses were similar in the initial angiogram, but narrowings were significantly more severe (p = 0.02) in the final angiogram (70 +/- 27% and 60 +/- 33%, respectively). New narrowings were more common in non-IRD than in non-D patients: there was a 23% increase in the number of narrowings in the follow-up angiogram in non-IRD patients compared with only 12% in non-D patients (p < 0.003). These new narrowings were more common (p = 0.01) in angioplasty arteries (57 narrowings on 420 arteries--13.6%) than in nonangioplasty arteries (54 narrowings on 639 arteries--8.5%). CONCLUSION: Restenosis is more common in IRD patients and explains the high rate of adverse cardiac events within the first year after coronary intervention in these patients (mainly target lesion revascularization). Disease progression (including new narrowings) is the main determinant of patient outcome > 1 year after coronary intervention and is accelerated in non-IRD compared with non-D patients.

Stents in total occlusion for restenosis prevention. The multicentre randomized STOP study. The Israeli Working Group for Interventional Cardiology.

AIMS: This multicentre randomized study set out to evaluate whether coronary stenting improves the results of successful balloon angioplasty for chronic total occlusion. Balloon angioplasty for chronic total occlusion has a high restenosis rate. Several reports have suggested that coronary stenting may decrease the likelihood of restenosis and reocclusion. METHODS AND RESULTS: Patients with total coronary artery occlusions who had an optimal PTCA result were randomized either to no further treatment or additional stent implantation. The AVE microstent was used and all patients were scheduled for a 1-, 3-, and 6-month clinical follow-up. Repeat coronary angiography to assess the rate and pattern of restenosis was performed at 6 months or earlier if clinically indicated. Ninety-six patients were enrolled in this study. The mean age was 59. 3+/-10.3 years and 15 were females. Forty-eight patients were randomized to the stent arm, receiving 52 stents (lengths 18-39 mm). Stent implantation was successful in all and there were no major procedure-related complications. Sixty-nine patients (72%) were restudied after 6 months. The binary restenosis rates (50%), in the PTCA arm were 70.9% with a minimal lumen diameter of 1.01+/-0.79 mm compared to 42.1% in the stent arm with a minimal lumen diameter of 1.63+/-1.02 mm (P=0.034). Reocclusion occurred in 7.9% in the stent group compared to 16.1% in the PTCA group. Restenosis in the PTCA group was focal in 88% of patients and occurred at the point of total obstruction (within 5 mm), compared to diffuse instent restenosis, which occurred in 54% of the patients in the stent group. CONCLUSION: Coronary stenting can significantly decrease the rate of restenosis and reocclusion of total occlusions. As restenosis in the stent group was more diffuse, care should be taken to implant short stents at the site of occlusion.

Reduction of congestive heart failure symptoms by very early fibrinolytic therapy in acute myocardial infarction: a long-term follow-up.

BACKGROUND: In patients with acute myocardial infarction (MI), early fibrinolytic therapy results in improved survival and preservation of ventricular function. The purpose of the study was to determine whether very early treatment also reduces the development of congestive heart failure. METHODS AND RESULTS: During the years 1984 to 1989, 358 consecutive patients with acute MI were treated with streptokinase, 161 within the first 1.5 hours from the onset of chest pain (group A) and 197 within 1.5 to 4.0 hours (group B). In 68, fibrinolysis was initiated in the prehospital setting pioneered by our group. Symptoms related to heart failure including dyspnea on exertion, fatigue, orthopnea, paroxysmal nocturnal dyspnea, nocturia, and peripheral edema, in addition to pulmonary edema events, were assessed during 5 years of follow-up. The evaluation was based on medical records and a detailed questionnaire, which was filled in by the investigators. A favorable significant effect of very early thrombolysis on the development of most of these limiting symptoms appeared 3 months after hospital discharge and persisted thereafter (P <.05). During hospitalization, pulmonary edema attacks occurred less frequently in patients from group A (23% vs 36.5%, P <.01). This difference persisted during 4 years of follow-up (13% vs 36%, P <.001). CONCLUSIONS: Our data demonstrate that very early fibrinolytic therapy results in a significant long-term reduction of congestive heart failure-related symptoms and thereby improves the quality of life in patients after MI.

Enhancing long-term ECG monitoring with graphic analysis of coupling intervals.

By graphically identifying patterns of ventricular ectopic beat (VEB) interval characteristics, we sought to enhance arrhythmia analysis, especially in long-term ECG monitoring. Coupling intervals as a function of preceding sinus RR intervals (CI/RR diagrams) with the aid of coupling interval and interectopic interval histograms were analyzed in 172 patients with frequent VEBs. Four distinct types of CI/RR diagrams were observed: horizontal-elongated (25 patients), linear (4 patients), triangular (37 patients), and clusters separated by dot-sparse areas (17 patients). In 89 patients, no definite pattern was discerned. The patients with elongated diagrams were significantly younger, had fixed coupling, uniform QRS complexes, and lacked periodicities in their interectopic interval histograms. The linear pattern was detected in a small group with rate-related VEBs. In the group with a triangular pattern, 30% of the patients exhibited interectopic periodicities suggesting parasystole. The patients with dot-sparse areas in the CI/RR diagrams had more variable coupling and predominantly more multiform QRS complexes. We conclude that CI/RR diagrams in conjunction with coupling interval and interectopic interval histograms enhance arrhythmia analysis by identifying patterns, such as those consistent with either fixed coupling, rate dependence, parasystole, or multiform VEBs.

Acute myocardial infarction--a late complication of intracoronary stent placement.

BACKGROUND: Myocardial infarction (MI) as the first indication of postangioplasty restenosis is extremely rare, and it has been speculated that the fibroproliferative restenotic lesion is less likely to undergo plaque rupture than the lipid-laden native atherosclerotic lesion. HYPOTHESIS: The present study was designed to examine whether intracoronary stent implantation affects this course. METHODS: In all, 994 consecutive patients who underwent angioplasty and intracoronary stent implantation in our hospital were reviewed retrospectively for the occurrence of MI. RESULTS: Eight patients (0.8%), all male and hypertensive, aged 33-83 years, presented with an MI due to stent occlusion more than 30 days following stenting (range: 35-398 days). In two patients, MI occurred 3 and 5 h, respectively, following completion of a maximal high-level exercise test that was negative for ischemia. Angiography revealed complete occlusion or significant stenosis of the stent in all eight patients, with an obvious intimal dissection in either edge of the stent in six patients. Except for gender and hypertension, no correlation was found with other risk factors, vessel involved, initial angiographic results, or with stent design, diameter, or length. CONCLUSIONS: Myocardial infarction as a late complication of successful stent implantation occurred in 0.8% of our patients. This is only the lower bound of the estimated frequency for such an event. We hypothesize that the transition point between the relatively fixed stent and the normal artery is exposed to high deformation stress which makes it vulnerable to rupture and dissection. Strenuous exercise and hypertension may increase the deformation stress and the risk of intimal rupture.

Changes in sinus RR interval patterns preceding ventricular ectopic beats: assessment with rate enhancement and dynamic heart rate trends.

Changes in heart rate preceding ventricular ectopic beats may be used to identify clinical subsets of patients. We evaluated RR interval patterns preceding ventricular ectopic beats with a rate enhancement method which estimates ventricular ectopic beat dependence on the sinus RR interval preceding the ventricular ectopic beat and the dynamic heart rate trend, which is based on the slope of the five RR intervals preceding the ventricular ectopic beat. Using these two methodologies in 176 patients with frequent ventricular ectopic beats we identified several unique subsets of patients: (1) bradycardia-enhanced patients were younger with a high proportion of males and longer, more variable coupling intervals; (2) tachycardia-enhanced patients exhibited sleep suppression of ventricular ectopic beats and had shorter, less variable coupling intervals; (3) patients with predominantly no change in RR preceding the ventricular ectopic beat were significantly older, with greater prevalence of cardiovascular disease and reduced sinus RR variability, indicating decreased autonomic nervous system activity. These two methods may serve as a basis for further investigations regarding the treatment and prognosis of ventricular ectopic beats.

The renal effect of low-dose dopamine in high-risk patients undergoing coronary angiography.

OBJECTIVES: The purpose of the study was to examine the potential renal protective effect of low-dose dopamine in high-risk patients undergoing coronary angiography. BACKGROUND: Contrast nephropathy is prevalent in patients with chronic renal failure (CRF) and/or diabetes mellitus (DM). Decreased renal blood flow due to vasoconstriction was suggested as a contributory mechanism. Low-dose dopamine has a dilatory effect on the renal vasculature. METHODS: Sixty-six patients with mild or moderate CRF and/or DM undergoing coronary angiography were prospectively double-blindedly randomized, to either 120 ml/day of 0.9% saline plus dopamine 2 microg/kg/min (Dopamine group) or saline alone (Control group) for 48 h. RESULTS: Thirty-three Dopamine-treated (30 diabetics and 6 with CRF) and 33 Control (28 diabetics and 5 with CRF) patients were compared. Plasma creatinine (Cr) level increased in the Control group from 100.6+/-5.2 before to 112.3+/-8.0 micromol/liter within five days after angiography (p = 0.003), and in the Dopamine group from 100.3+/-5.4 before to 117.5+/-8.8 micromol/liter after angiography (p = 0.0001), respectively. There was no significant difference in the change of Cr level (deltaCr) between the two groups. However, in a subgroup of patients with peripheral vascular disease (PVD), deltaCr was -2.4+/-2.3 in the Control group and 30.0+/-12.0 micromol/liter in the Dopamine group (p = 0.01). No significant difference occurred in deltaCr between Control and Dopamine in subgroups of patients with preangiographic CRF or DM. CONCLUSIONS: Contrast material caused a small but significant increase in Cr blood level in high-risk patients. There is no advantage of dopamine over adequate hydration in patients with mild to moderate renal failure or DM undergoing coronary angiography. Dopamine should be avoided in patients with PVD exposed to contrast medium.

Long-term outcome of patients with very long stents for treatment of diffuse coronary disease.

OBJECTIVES: The study sought to determine the 6-month clinical outcome of patients who underwent implantation of very long coronary stents to treat diffuse disease and/or long dissections and to compare the findings with those reported in the literature for patients who underwent implantation of multiple short coronary stents. BACKGROUND: New designs of flexible stents enable the implantation of long stents rather than multiple short, older design stents. The initial experience is very promising but the long-term outcome has not been described yet. METHODS: Fifty-seven consecutive patients in whom 67 long stents (>/=30 mm) were successfully deployed were included in this study. Six-month clinical and angiographic follow-up was prospectively collected. Patients with recurrent angina underwent coronary angiography without further testing. Patients who remained asymptomatic at the 6-month follow-up visit underwent positron emission tomographic imaging, and those with results suggestive of ischemia underwent coronary angiography. A combined study end point was defined as death, myocardial infarction, and the need for target vessel revascularization. RESULTS: Only 1 patient (2%) reached a study end point at hospital discharge. An additional 20 patients (total 21 patients [37%]) reached an end point by 6 months. The outcome was not influenced by the clinical presentation (stable or unstable angina) or by the indication for stenting (elective or emergency). Predictors for adverse outcome were multiple stents per narrowing (63% vs 29%, P <. 04), and stents smaller than 3.5 mm (49% vs 22%). Narrowing and stent length were not predictive of a study end point in narrowings that were successfully treated by a single long stent. CONCLUSIONS: Elective stenting provides an effective solution for patients with diffuse coronary disease provided that a single long stent (usually <40 mm) can cover the full length of the narrowing. The results are better when vessels larger than 3 mm are treated. Compared with multiple short stents, implantation of a single long stent is probably at least as effective, and the procedure is quicker and cheaper and thus should be the preferred approach.

Simulation of ventricular arrhythmias using a re-entry model algorithm.

The present study employs a computer simulation of the timing of normal and abnormal ventricular activation according to a re-entry model. A wide variety of arrhythmia patterns similar to those obtained in clinical settings may be simulated by using an algorithm which is based on parameters such as the sinus RR interval (RR), the refractory period, the coupling interval between normal activation and re-entry and the coupling interval between one re-entry and a subsequent re-entry (CV). By varying RR and CV the results of the simulation may show transition between different types of arrhythmia such as ventricular tachycardia, bigeminy, trigeminy and more widely separated ventricular ectopic beats such as in concealed bigeminy. The algorithm provides a basis for the study of re-entry, a major mechanism in the genesis of ventricular arrhythmias.

Right ventricular myocardial bridge in a patient with pulmonary hypertension--a case report.

Myocardial bridge is a not uncommon finding in routine diagnostic coronary angiography or pathological examination of the heart. It is almost always confined to the left ventricle and the left anterior descending coronary artery. This report describes a patient with chronic lung disease, severe left ventricular dysfunction, and pulmonary hypertension in whom coronary angiography revealed bridging of the right ventricular branch of the right coronary artery.

Quantitative videodensitometric technique for verification of optimal coronary stent implantation.

Coronary angiography is not sensitive enough to define the results of stent implantation. Intravascular ultrasound defines accurately the anatomy of the vessel and the stent within the vessel and is thus considered the gold standard for defining the results of stent implantation. However intravascular ultrasound is an additional invasive procedure that is time consuming and expensive. This study describes a new simple quantitative videodensitometric technique, developed specifically to assess the results of stent implantation and compares the findings to intravascular ultrasound. In the proposed algorithm for the videodensitometric analysis, density profiles were constructed perpendicular to the long axis of the stented segment and each one was compared (after background subtraction) with a theoretic profile of a normal artery at that location. Density deficit index was determined at each point from the actual and theoretic profiles and a global volumetric density deficit index was calculated for each stent by integrating the deficit indices at all points along the stent. Similarly an area stenosis was determined at each point along the stent (using the stent and normal vessel cross sectional areas as defined by intravascular ultrasound) and the global volumetric stent stenosis was calculated by integrating the values of area stenosis along the stent. Twenty-five patients were evaluated immediately before and after coronary stent implantation. Global density deficit index improved from 66.1+/-16.4% before (after last balloon inflation) to 44.4+/-11.1% after stenting (P < 0.001). The shape of the curves of densitometric deficit indices along each stent were similar to the equivalent area stenosis curves as determined by intravascular ultrasound. The correlation (R = 0.74) between the global volumetric density deficit index and the global volumetric stent stenosis is statistically significant (P < 0.001). In conclusion, in this preliminary report we describe a new algorithm for videodensitometric analysis of the results of coronary stent implantation. As compared with intravascular ultrasound this method does not require an additional invasive procedure and it is quick cheap and easy to carry out.

Thrombolysis in acute myocardial infarction improves prognosis and prolongs life but will increase the prevalence of heart failure in the geriatric population.

This paper will review the hypothesis that early complete thrombolytic therapy in acute myocardial infarction reduces mortality and improves prognosis. ACE inhibitors improve remodelling and anti-platelet drugs or interventional procedures prevent reocclusion of the infarct related coronary artery. Most patients are left with significant myocardial damage and this effect is cumulative with subsequent infarction. The average age of death has increased by 10 years in the last three decades, so that many older patients survive. They have survived acute myocardial infarction and we now have a significant population with important heart failure despite good thrombolytic therapy.

Prevention of congestive heart failure by early, prehospital thrombolysis in acute myocardial infarction: a long-term follow-up study.

The long term impact of pre-hospital thrombolysis in acute myocardial infarction on the subsequent development of heart failure symptoms was investigated in 362 consecutive patients. The pre hospital strategy, used in 61 patients, allowed for very early administration of streptokinase, within 1.2+/-0.6 (mean+/-S.D.) hours from pain onset. In contrast, 294 patients treated in hospital received lytic treatment within 2.0+/-0.9 hours. The pre hospital group showed faster reperfusion, as measured by the time to peak creatine kinase and to ST segment recovery, but only a slightly better ventricular function, as compared to hospital treated patients. Heart failure symptoms were significantly reduced in the pre hospital group during hospitalization and at long term follow up: there were less dyspnea, fatigue, orthopnea, nocturnal dyspnea, nocturia, peripheral edema and episodes of pulmonary edema. Angina was reduced as well. We conclude that the initial benefit of prehospital thrombolysis translates into long term reduction of heart failure symptoms, thus improving quality of life.

Coronary arteriovenous malformations in a patient with hereditary hemorrhagic telangiectasia--a case report.

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu) disease is characterized by cutaneous, mucosal, and visceral vascular anomalies. Two patients were previously described with coronary artery aneurysms (ectasia) associated with this disease. This report describes a patient with Osler-Weber-Rendu disease in whom multiple coronary arteriovenous malformations were identified during coronary angiography. The patient presented with anginal chest pain resulting from severe anemia. Upper gastrointestinal endoscopy revealed multiple angiodysplastic lesions throughout the esophagus and stomach.

New indicator for stent covering area.

A small gap between stent struts is essential to support the vessel wall, prevent elastic recoil, and prevent intimal flaps from prolpasing into the lumen. We defined Gap Index as the ratio of strut width divided by the percent of the vessel wall area covered by the stent metal, and proved mathematically that this index relates inversely to the total length of stent struts (or coil), and directly related to stent cell size. Twenty-four (12 tubular and 12 coil) stents from 17 manufacturers were analyzed. Strut width in the tubular and coil groups was 354.1 +/- 276.0 and 955.9 +/- 553.9 microm, respectively (P < 0.001). The relative metallic surface area (RMS) in the tubular and coil groups for 3 mm stent diameter was 16.0 +/- 4.6 and 10.6 +/- 3.7%, respectively (P < 0.005). Great variations in Gap Index were found amongst different stents, with up to 100-fold. Gap Index in the tubular and coil groups for 3 mm stent diameter was 24.4 +/- 21.7 and 105.8 +/- 97.5 units, respectively (P = 0.001). Thus, coil stents have a smaller relative metallic surface area despite increased strut width. This is the result of reduced total strut length and fewer and larger cells, as represented by a higher Gap Index. This information may be useful for new stents designs.

Two-year follow-up in pediatric and adult patients with single-pass lead VDD pacing system.

VDD pacing follow-up is similar in pediatric and adult patients. Atrial and ventricular pacing parameters are stable during 2-year follow-up in children, and single-pass lead VDD pacing is recommended when the sinus node function is normal.

Diffuse narrowing of coronary arteries in diabetic patients: the earliest phase of coronary artery disease.

Coronary arteries in diabetic patients appear to be narrower than in normal subjects, but this has not been examined systematically. To investigate this hypothesis we reviewed the data of 711 consecutive patients with angiographically 'normal coronary arteries'. Excluded were patients with valvular, myocardial or pericardial disease, and patients with hypertension or hyperlipidemia. Thirteen diabetic patients (10 men) and 22 nondiabetic persons (8 men) constituted the study and control groups, respectively. The diameters of the coronary arteries and their branches were measured and adjusted for body surface area. The sum of the proximal left anterior descending (LAD), circumflex and right coronary arteries (RCA) was calculated and defined as total coronary diameter (TCD). The sum of the distal LAD, first diagonal, first marginal and distal RCA was calculated and defined as total distal coronary diameter (dTCD). The clinical data of both groups were comparable. Adjusted TCD for body surface area was 5.4 +/- 1.1 and 6.5 +/- 1.1 mm/m2 (p < 0.05) in diabetics and nondiabetics, respectively, and adjusted dTCD was 4.9 +/- 1.2 and 6.1 +/- 1.2 mm/m2 (p = 0.01) in diabetics and normal subjects, respectively. Specific arteries and branches that were significantly smaller in diabetics included: left main coronary artery, distal LAD, first diagonal, proximal RCA, distal RCA, right ventricular branch, and posterolateral and posterior descending artery of RCA origin. Gender was not a confounding factor since the control group had a larger proportion of women and still larger arteries than the diabetic group. In conclusion, coronary arteries and their branches in diabetic patients have smaller diameters than normal subjects. This may be due to increased coronary tone, diffuse mild atherosclerosis or both.