Left ventricular muscle mass and elevated heart rate are associated with coronary plaque disruption.

BACKGROUND: Plaque disruption is the central pathophysiological mechanism underlying acute coronary syndromes and the progression of coronary atherosclerosis. There exists only scant information about the factors that are associated with its development. The aim of the current study was to analyze the contribution of hemodynamic forces in the pathogenesis of plaque disruption. Plaque disruption was diagnosed by coronary angiography of stenosed but not completely occluded coronary arteries. METHODS AND RESULTS: This study retrospectively analyzed 106 patients who underwent 2 coronary angiography procedures within 6 months. We investigated 53 patients with initially smooth stenoses who developed plaque disruption by the time of the second coronary angiogram and compared these patients with 53 age- and sex-matched individuals with smooth stenoses without angiographic signs of plaque disruption. The 2 groups were compared by analyzing central hemodynamics, echocardiographic measurements, and cardiovascular medication use. Logistic regression analysis identified positive associations between plaque disruption, left ventricular muscle mass >270 g, and a mean heart rate >80 bpm and a negative association with the use of beta-blockers. CONCLUSIONS: The associations documented by our investigation indicate that hemodynamic forces may play a crucial role in the pathogenesis of plaque disruption. These findings may help to identify patients who are at an increased risk of plaque disruption and who might gain benefit from pharmacological interventions aimed at reducing heart rate, for example, by the use of beta-blockers, or a reduction of left ventricular hypertrophy.

Risk factors for the development of restenosis following stent implantation of venous bypass grafts.

OBJECTIVE: To analyse the variables involved in the high restenosis rate following stent implantation in coronary artery bypass grafts. DESIGN: A retrospective analysis of a consecutive group of patients attending a tertiary centre. PATIENTS: The long term angiographic outcome of 219 stent implantations for individual lesions performed in 191 patients was investigated. Multivariate analysis correlated clinical, procedural, and angiographic variables with the incidence of angiographic restenosis, defined as diameter stenosis > 50% at follow up. RESULTS: Angiographic restenosis was observed in 34% of lesions treated. Multiple logistic regression analysis defined diabetes mellitus (odds ratio 6.91, 95% confidence interval (CI) 2.43 to 9.69), graft recanalisation (2.89, 95% CI 1.18 to 6.63), lesion at the aortic anastomosis (6.98, 95% CI 2.77 to 21.31), lesion at the coronary anastomosis (3.01, 95% CI 1.19 to 7.69), high diameter stenosis after stent placement (7.21, 95% CI 2.66 to 16.81), placement of long stents (2.73, 95% CI 1.09 to 7.39), and implantation of more than one stent (7.31, 95% CI 2.08 to 19.96) as independent predictors of graft in-stent restenosis. CONCLUSIONS: There appears to be a specific risk factor constellation contributing to the high restenosis rate following stent implantation in venous bypass grafts. Critical consideration of these variables may help identify patients who are poor candidates for stent implantation and who may benefit from a different approach.

Intracoronary administration of dipyridamole prior to percutaneous transluminal coronary angioplasty provides a protective effect exceeding that of ischemic preconditioning.

BACKGROUND: Ischemic preconditioning renders hearts more resistant to the deleterious consequences of ischemia. Adenosine is an important mediator in the induction and maintenance of ischemic preconditioning. Percutaneous transluminal coronary angioplasty (PTCA) allows the investigation of the consequences of ischemia in humans. The severity of myocardial ischemia decreases with subsequent balloon inflations during the course of PTCA. OBJECTIVE: To compare the effect of intracoronary administration of dipyridamole with the effect of consecutive balloon inflations. METHODS: We investigated 30 patients undergoing PTCA of the left anterior descending coronary artery in the setting of stable angina pectoris. Patients were randomly allocated to be administered either 0.5 mg/kg body weight dipyridamole intracoronarily or an equal amount of saline. Patients administered saline served as a control group. All patients were subjected to three consecutive balloon inflations. Severity of myocardial ischemia was assessed in terms of severity of chest pain, electrocardiographic signs of ischemia, and duration of balloon inflation tolerated. RESULTS: Patients administered dipyridamole intracoronarily tolerated significantly longer durations of balloon inflation than did patients in the control group. Severity of anginal pain and extent of electrocardiographic signs of ischemia were significantly lower after intracoronary administration of dipyridamole. The reductions in anginal pain and ST-segment shift caused by intracoronary administration of dipyridamole during the first balloon inflation were even more pronounced than the protection that was afforded by the third balloon inflation for patients in the control group. CONCLUSIONS: Intracoronary administration of dipyridamole prior to PTCA is associated with a significant gain in tolerance of ischemia. The protection afforded by intracoronary administration of dipyridamole is even more pronounced than the effect of ischemic preconditioning.

[Restenosis predictors after stent implantation of venous aortocoronary bypass grafts]. / Restenose-Prädiktoren nach Stent-Implantation aortokoronarvenöser Bypassgefässe.

Follow-up studies after stent implantation of native coronary arteries have reported reduced rates of angiographic restenosis. In contrast, stent implantation in the treatment of obstructive disease of coronary artery bypass grafts is complicated by higher restenosis rates. We sought to determine, if different predictors contribute to the high restenosis rate following stent implantation of coronary artery bypass grafts. We investigated long-term angiographic outcome of 205 stent implantations performed in 177 patients. Multivariate analysis correlated clinical, procedural and angiographic variables with the incidence of angiographic restenosis defined as diameter stenosis > 50% at follow-up. Angiographic restenosis was observed in 34% of lesions treated. Multiple logistic regression analysis defined diabetes mellitus (OR 6.89, CI 2.41-9.69), graft recanalization (OR 2.69, CI 1.08-6.63), lesion at the aortic anastomosis (OR 6.98, CI 2.76-19.25), lesion at the coronary anastomosis (OR 2.95, CI 1.18-7.49), high diameter stenosis after stent placement (OR 7.01, CI 2.64-15.71), placement of long stents (OR 2.78, CI 1.11-7.36) and implantation of more than one stent (OR 7.34, CI 2.08-20.15) as independent predictors of graft in-stent restenosis. Critical consideration of these variables may help to identify patients who are poor candidates for stent implantation and who may benefit from different interventional approaches.

Preconditioning during percutaneous transluminal coronary angioplasty by endogenous and exogenous adenosine.

BACKGROUND: The purpose of this study was to assess whether pharmacologic preconditioning by exogenous or endogenous adenosine prevents the deterioration of hemodynamic function and left ventricular performance during percutaneous transluminal coronary angioplasty (PTCA). Ischemic preconditioning renders the heart more resistant to subsequent ischemia. Adenosine plays a key role in its pathogenesis. Coronary angioplasty is a suitable model for the induction of myocardial ischemia. METHODS AND RESULTS: We investigated 30 patients receiving PTCA of the left anterior descending coronary. Patients were randomly allocated to either dipyridamole, leading to the liberation of endogenous adenosine (0.5 mg/kg body weight, intracoronary), exogenous adenosine (20 mg intracoronary), or an equal amount of saline. Chest pain, tolerated inflation time, and ST-segment shift were registered. Left ventricular hemodynamics, isovolumetric phase indexes, indexes of volume, ejection fraction, and indexes of diastolic dysfunction were analyzed. Patients receiving endogenous or exogenous adenosine tolerated longer balloon inflation times (dipyridamole, 208 +/- 23 seconds; adenosine, 188 +/- 41 seconds; control, 153 +/- 36 seconds; P <.05). Deterioration of left ventricular ejection fraction was less severe after adenosine (72% +/- 5% before PTCA vs 64% +/- 6% during angioplasty; P =.11) and could be prevented by intracoronary dipyridamole (69% +/- 12% before PTCA vs 68% +/- 11% after PTCA; P <. 01) compared with the control group (71% +/- 7% before PTCA vs 60% +/- 7% during angioplasty). CONCLUSIONS: Intracoronary application of exogenous adenosine and liberation of endogenous adenosine increase the tolerance to ischemia and prevent deterioration of left ventricular function during ischemia. These findings can be attributed to ischemic preconditioning. However, endogenous adenosine exceeds the protective effects of exogenous adenosine.

Effect of adjunctive intracoronary adenosine on myocardial ischemia, hemodynamic function and left ventricular performance during percutaneous transluminal coronary angioplasty: clinical access to ischemic preconditioning?

BACKGROUND: Ischemic preconditioning has been defined as a mechanism that renders the heart more resistant to subsequent ischemia. Adenosine plays an important role in the pathogenesis of ischemic preconditioning. OBJECTIVE: To assess whether intracoronary administration of adenosine prevents the deterioration of left ventricular performance and hemodynamic function by allowing adaptation to myocardial ischemia in the setting of percutaneous transluminal coronary angioplasty (PTCA). DESIGN: This was a prospectively randomized doubly blinded trial. METHODS: We investigated 20 patients undergoing PTCA of the left anterior descending coronary artery supplying myocardium with normal left ventricular function in the setting of stable angina pectoris. Patients were randomly allocated to be administered adenosine intracoronarily (20 mg/10 min) or an equal amount of saline, providing a control population. Results of standardized chest pain questionnaires, tolerated inflation times, ST-segment shifts, left ventricular and aortic pressures, isovolumetric phase indexes, and indexes of volume and ejection fraction during the course of PTCA between the two groups were compared. RESULTS: Patients administered adenosine tolerated significantly longer balloon-inflation times (188 +/- 41 versus 153 +/- 36 s; P = 0.03), which were associated with less pronounced signs of ischemia, and exhibited less deterioration of isovolumetric phase indexes during PTCA. Deterioration of left ventricular ejection fraction was slightly less severe with adenosine (72 +/- 5% before PTCA versus 64 +/- 6% during angioplasty) than it was for the control group (71 +/- 7% before PTCA versus 60 +/- 7% during angioplasty; P = 0.11). CONCLUSIONS: Intracoronary application of adenosine prior to coronary angioplasty increases tolerance of ischemia and prevents deterioration of left ventricular hemodynamics during ischemia. One potential explanation of these results is that induction of ischemic preconditioning took place.

Adjunctive intracoronary dipyridamole in the interventional treatment of small coronary arteries: a prospectively randomized trial.

BACKGROUND: Patients undergoing intracoronary stent placement or balloon angioplasty for the treatment of small coronary arteries are at an increased risk of an adverse outcome from a higher incidence of abrupt closure and restenosis. Intracoronary thrombus formation plays a key role in the pathogenesis of abrupt vessel closure and of restenosis. Dipyridamole prevents platelet aggregation by a mechanism that differs from aspirin. The purpose of this study was to investigate the effect of intracoronary dipyridamole on acute complications and restenosis after percutaneous transluminal coronary angioplasty. METHODS: In a prospectively randomized study including 491 dilatations of coronary arteries with a diameter <2.75 mm, additional intracoronary application of dipyridamole was compared with conventional pretreatment consisting of heparin and aspirin. Study end points were defined as incidence of abrupt vessel closure, myocardial infarction, angiographic restenosis, and target vessel revascularization rate. RESULTS: Intracoronary dipyridamole was associated with a significant reduction of abrupt vessel closure (2.8% vs 8.6%; P =.005) and a nonsignificant reduction of myocardial infarction (1.6% vs 4.5%; P =.07) after percutaneous transluminal coronary angioplasty. Net gain 6 months after angioplasty was significantly higher in the dipyridamole group (0.60 +/- 0.35 mm vs 0.42 +/- 0.34 mm; P <.001). However, dipyridamole failed to reduce the incidence of angiographic restenosis (41.6% vs 49.1%; P =.11) and target vessel revascularization rate (20.6% vs 269%; P =.12). CONCLUSIONS: Intracoronary dipyridamole reduces the incidence of adverse cardiovascular events in the first 48 hours after balloon angioplasty of small coronary arteries. Reduction of restenosis rates failed to reach statistical significance. However, a significant increase in net gain was observed. Thus intracoronary application of dipyridamole should be considered in the treatment of small coronary arteries when intracoronary stenting is not appropriate.

Intracoronary dipyridamole reduces the incidence of abrupt vessel closure following PTCA: a prospective randomised trial.

OBJECTIVES: To investigate the effect of intracoronary dipyridamole on the incidence of abrupt vessel closure, myocardial infarction, necessity for bypass grafting, and death following percutaneous transluminal coronary angioplasty (PTCA). PATIENTS: Patients were randomly allocated to receive either conventional pretreatment (heparin 15 000 IU and aspirin 500 mg intravenously) or additional intracoronary dipyridamole (0.5 mg/kg bodyweight). Dipyridamole was administered in 550 PTCA procedures (455 interventions in men, mean (SD) age 59.2 (8.4) years; 74 acute coronary syndromes), while conventional pretreatment was administered in 544 interventions (444 interventions in men 58.3 (7.9) years old; 81 acute coronary syndromes). In 53 interventions bail out stenting was performed for threatened abrupt vessel closure. RESULTS: Intracoronary dipyridamole significantly reduced the incidence of abrupt vessel closure (odds ratio 0.42. 95% confidence interval (CI) 0.22 to 0.79). While abrupt vessel closure occurred in 6.1% of interventions following conventional pretreatment, dipyridamole reduced the incidence to 2.5%. Restricting the analysis to balloon angioplasty, this reduction was observed in patients with stable angina (odds ratio 0.49, 95% CI 0.23 to 0.96) as well as in those with acute coronary syndromes (odds ratio 0.29, 95% CI 0.09 to 0.87). Reduction of secondary end points in the dipyridamole treated patients failed to reach significance in the PTCA group. CONCLUSIONS: Intracoronary dipyridamole before PTCA reduces the incidence of abrupt vessel closure following PTCA for stable angina and acute coronary syndromes.

[Interventional catheter treatment of bypass graft stenosis: comparison of intracoronary stent implantation and balloon angioplasty]. / Katheterinterventionelle Therapie stenosierter Bypassgefässe. Vergleich zwischen intrakoronarer Stent-Implantation und Ballonangioplastie.

BACKGROUND AND OBJECTIVE: Balloon angioplasty of a stenosed bypass graft has a much higher risk of recurrent stenosis than dilatation of a stenosed native coronary artery. Intracoronary stent implantation has established itself as the better treatment of native coronary artery stenosis than conventional balloon angioplasty. However, there is still uncertainty whether intracoronary stent implantation in stenosed bypass vessels gives better long-term results than conventional balloon angioplasty. PATIENTS AND METHODS: Results were retrospectively analyzed of unrandomized 224 primarily successful interventions--122 balloon dilatations and 102 stent implantations--performed between January 1996 and June 1998 on stenosed coronary bypass grafts, re-examined by coronary angiography an average of 6 months later. All but 11 patients were on combined aspirin and ticlopidine antiplatelet aggregation treatment. RESULTS: There was a significantly lower 6-month restenosis rate (30.4%) after stent implantation than after balloon dilatation (51.6%). The re-intervention rate was also significantly lower after stent implantation. CONCLUSION: These data suggest that stent implantation of stenosed coronary bypass grafts under cover of platelet-aggregation inhibition with aspirin and ticlopidine provides a lower restenosis and thus higher revascularization rate than conventional balloon dilatation.

Prior cytomegalovirus infection and the risk of restenosis after percutaneous transluminal coronary balloon angioplasty.

BACKGROUND: Restenosis is a common problem after all revascularization procedures in atherosclerotic coronary arteries. Reactivated human cytomegalovirus (CMV) has been detected in tissues of restenotic vascular lesions and was hypothesized to be a contributing pathogenic factor. Recent data suggest an association of restenosis after optimal coronary atherectomy with CMV serostatus, and a possible role of antiviral therapy was discussed. We therefore tested the hypothesis that prior CMV infection might be a risk factor for restenosis after conventional coronary balloon angioplasty (PTCA). METHODS AND RESULTS: We analyzed 92 consecutive patients who had been admitted for control angiography after previous PTCA within a mean interval of 6 months. Anti-CMV antibodies were measured as an indicator of prior CMV infection and latency. The coronary angiograms before PTCA, directly after, and 6 months later were analyzed quantitatively. Sixty-five percent of the patients were CMV-positive. Before PTCA, the degree (mean+/-SD) of stenosis was 69+/-10% in CMV-positive and 68+/-8.3% in CMV-negative subjects. PTCA resulted in a residual stenosis of 39% in both groups. After 6 months, the late losses of luminal diameter in the CMV-positive and -negative groups were 11+/-13% and 12+/-15%, respectively (P=0.658). In an ANCOVA with 25 potential risk factors for restenosis, CMV serostatus was not significantly associated with restenosis development. CONCLUSIONS: Our data indicate that prior CMV infection, in contrast to optimal atherectomy, is not associated with chronic restenosis after conventional coronary balloon angioplasty. The results do not support a possible benefit from antiviral therapy.

[Effect of intracoronary dipyridamole administration on the incidence of restenosis after PTCA. A prospective randomized study]. / Einfluss einer intrakoronaren Dipyridamol-Applikation auf die Inzidenz der Restenose nach PTCA. Eine prospektiv randomisierte Untersuchung.

BACKGROUND: Restenosis after PTCA remains a serious long-term complication of balloon angioplasty occurring in 30 to 50% of patients. Platelets play a crucial role in the pathogenesis of restenosis following PTCA. Dipyridamole has been shown to inhibit platelet aggregation in humans. Its action as an antithrombotic drug can be attributed to different mechanisms including inhibition of platelet phosphodiesterase and inhibition of the cellular uptake of adenosine. PATIENTS AND METHODS: The purpose of the following study was to investigate the effect of an intracoronary infusion of dipyridamole on the incidence of angiographic and clinical restenosis. In 763 balloon angioplasties patients were randomly allocated to receive either conventional pretreatment (heparin 15000 IE, aspirin 500 mg i.v.) or an additional intracoronary infusion of dipyridamole (0.5 mg/kg body weight). Conventional pretreatment was performed in 388 interventions (61 interventions in women, age 60.5 +/- 8.7 years; 47 interventions for acute coronary syndromes); in 375 interventions additional intracoronary dipyridamole was infused (58 interventions in women, age = 59.6 +/- 9.6 years; 57 interventions for acute coronary syndromes). RESULTS: As compared to conventional pretreatment intracoronary dipyridamole application was associated with a reduction in angiographic restenosis from 43.0% to 36.8% and a reduction of target vessel revascularisation by 15.5% but failed to reach statistical significance. These results were due to an increase in net gain following dipyridamole application. CONCLUSION: Intracoronary pretreatment with dipyridamole prior to PTCA fails to reduce the incidence of angiographic restenosis and target vessel revascularisation significantly. However, a moderate improvement of long-term follow-up can be achieved.

[Is there a prognostic indication for PTCA?]. / Gibt es eine prognostische Indikation zur PTCA?

Coronary angioplasty is classically indicated to remove a high grade stenosis of a major coronary vessel supplying a large myocardial territory in a symptomatic patient with proven myocardial ischemia. The coronary anatomy has to be suitable for PTCA to ensure a high success rate for the procedure. PTCA is performed to remove symptoms and myocardial ischemia to improve the prognosis of the patient. In contrast to this, the term "prognostic indication" describes an interventional approach to an angiographically documented high grade stenosis in an asymptomatic patient without proven myocardial ischemia thereby hoping to improve the prognosis of this patient. It has to be expected, that up to 20% of all patients treated by balloon angioplasty and 10% of all stented patients are treated with respect to a "prognostic indication". Until now, there are no statistically significant large-scale studies supporting a benefit of an interventional therapy performed with a "prognostic indication" in asymptomatic patients without ischemia. Nevertheless, some certain subgroups of patients may be candidates for a "prognostic indication" to angioplasty compared to the results of medical therapy. In patients treated interventionally for a "prognostic indication" the acute and long-term individual risk of the underlying coronary disease must be carefully weighted against the risk of the interventional procedure.

Acute complications and restenosis in women undergoing percutaneous transluminal coronary angioplasty. Is it possible to define sex differences and to determine risk factors?

BACKGROUND: Several investigators report a sex bias in the treatment of coronary artery disease. This study attempts to define sex differences in the outcome of percutaneous transluminal coronary angioplasty (PTCA) and to determine risk factors contributing to these results. RESULTS: Data were collected from 1082 patients (887 men and 195 women). In women, the risk of abrupt vessel closure (8.1% versus 2.5%, odds ratio 3.46) and of myocardial infarction (6.2% versus 1.2%, odds ratio 5.58) following PTCA for stable angina pectoris was significantly increased. History of myocardial infarction and PTCA of a vessel of less than 3.0 mm diameter predicted abrupt vessel closure in women. Age and cardiovascular risk factors were not predictors. The incidence of restenosis did not differ significantly (angiographic restenosis in women 36.1% versus 40.8% in men, P=0.34). CONCLUSIONS: A significantly increased risk of acute complications could only be documented in women undergoing PTCA for stable angina pectoris and not in acute coronary syndrome. Long-term outcome was similar between the two sexes.

[Intracoronary dipyridamole reduces the incidence of acute coronary vessel occlusion in percutaneous transluminal coronary angioplasty--a prospective randomized study]. / Dipyridamol intrakoronar reduziert die Inzidenz des akuten Koronargefässverschlusses bei der perkutanen transluminalen Koronarangioplastie--Eine prospektiv randomisierte Untersuchung.

Even in the era of coronary stenting, acute coronary artery occlusion continues to represent a significant limitation of percutaneous transluminal coronary angioplasty (PTCA). Despite application of heparin and aspirin, abrupt vessel closure still occurs in 2-8%, depending on the definition applied. Especially patients receiving PTCA for acute coronary syndromes are at high risk for abrupt vessel closure. The formation of an intracoronary thrombus plays a central role in the pathogenesis of abrupt vessel closure. Dipyridamole induces dilatation of coronary arteries and prevents platelet aggregation by a mechanism that differs from that of aspirin. The primary purpose of the study was to evaluate whether adjunctive local intracoronary therapy with dipyridamole could reduce the incidence of coronary artery occlusion following PTCA. Secondary endpoints were defined as myocardial infarction, necessity for bypass grafting, and death. In 939 PTCA procedures performed for stable angina and in 155 angioplasty procedures for acute coronary syndromes (unstable angina, acute myocardial infarction), patients were randomized to receive conventional pretreatment consisting of heparin 15,000 I.E. and aspirin 500 mg i.v. or additional intracoronary infusion of dipyridamole (0.5 mg/kg body weight). Dipyridamole was applied in 550 interventions (455 interventions in men, 95 interventions in women, age = 59.2 +/- 8.4; 74 emergency procedures); conventional pretreatment was performed in 544 interventions (444 interventions in men, 100 interventions in women, age 58.3 +/- 7.9; 81 emergency procedures). Intracoronary application of dipyridamole resulted in a significant reduction in the incidence of abrupt vessel closure following PTCA. This significant reduction was observed in patients presenting with stable ischemia as well as in patients receiving PTCA for acute coronary syndromes. Concerning secondary end points, intracoronary application of dipyridamole did not affect the need for bypass grafting or the incidence of death following PTCA. Intracoronary application of dipyridamole was associated with a reduction in the incidence of myocardial infarction following PTCA which, however, failed to reach significance.

[Acute coronary vessel occlusion after PTCA--possibility of risk stratification using quantitative coronary angiography, clinical determinants and laboratory chemistry parameters]. / Der akute Koronargefässverschluss nach PTCA--Möglichkeit der Risikostratifizierung mittels quantitativer Koronarangiographie, klinischer Determinanten und laborchemischer Parameter.

Abrupt vessel closure of the dilated vessel continues to represent a significant limitation of coronary angioplasty. Despite increasing operator experience and improved technology, abrupt vessel closure continues to represent the most important complication of balloon angioplasty. Intracoronary stent implantation and pharmaceutical blockade of the GPIIb/IIIa receptor serve as effective tools in the prevention of abrupt vessel closure without completely resolving this problem. About 50% of patients presenting with abrupt vessel closure exhibit additional complications including myocardial infarction, necessity of CABG or death occurring in up to 10% of acute occlusions. The purpose of this study is to evaluate if quantitative coronary angiography and assessment of clinical and laboratory data allows risk stratification concerning the probability of abrupt vessel closure. PTCA in the setting of acute coronary syndrome is associated with a markedly increased risk of abrupt vessel closure, indicating that different risk factors may contribute to the development of abrupt vessel closure in patients presenting with stable angina or acute coronary insufficiency syndromes. 798 uncomplicated PTCA procedures for stable angina pectoris were compared with 68 interventions that were complicated by abrupt vessel closure. Furthermore, 133 successful angioplasty procedures for acute coronary syndromes defined as acute myocardial infarction or unstable angina pectoris were matched with 31 procedures for acute coronary syndromes with consecutive abrupt vessel closure. In patients presenting with stable angina pectoris stenosis length, stenosis eccentricity, minimal lumen diameter, degree of the stenosis after angioplasty, female gender, and fibrinogen could be defined as independent predictors of abrupt vessel closure. In acute coronary syndromes, only minimal lumen diameter, recanalization of completely occluded coronary arteries and fibrinogen were associated with an increased risk of abrupt vessel closure.

Pharmacologic myocardial protection during percutaneous transluminal coronary angioplasty by intracoronary application of dipyridamole: impact on hemodynamic function and left ventricular performance.

OBJECTIVES: The aim of this study was to investigate whether intracoronary infusion of dipyridamole represents a suitable tool for preventing deterioration of left ventricular performance and hemodynamic function during percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND: Coronary angioplasty represents a suitable model for establishing myocardial ischemia in humans. Balloon inflation is usually accompanied by significant deterioration in left ventricular systolic and diastolic properties. A brief episode of ischemia followed by reperfusion, termed preconditioning, has been identified as a mechanism for rendering the myocardium more resistant to ischemia. Adenosine is considered an important mediator of preconditioning. Dipyridamole is an important drug that interferes with myocardial adenosine metabolism by inhibiting its cellular reuptake. METHODS: In 20 patients undergoing elective coronary angioplasty of a major vessel, assessment of angiographic left ventricular performance and hemodynamic variables was performed before, during and after PTCA. Patients were randomly allocated to pretreatment with intracoronary infusion of dipyridamole before percutaneous transluminal coronary angioplasty (10 patients) or conventional pretreatment without dipyridamole (10 patients). RESULTS: Dipyridamole pretreatment resulted in significant preservation of systolic and diastolic left ventricular performance during percutaneous transluminal coronary angioplasty, as documented by an unaffected global ejection fraction (vs. a deterioration of 29.2% with conventional pretreatment, p < 0.01) and an increment in diastolic stiffness of only 12.7% (vs. an increment of 57.3% with conventional pretreatment, p < 0.01). Apart from one instance of coronary steal phenomenon, no significant side effects of dipyridamole infusion could be detected. CONCLUSIONS: It is concluded that intracoronary application of dipyridamole may result in the induction of myocardial preconditioning by improving systolic and diastolic ventricular performance during percutaneous transluminal coronary angioplasty, thereby potentially reducing the risk of the angioplasty procedure.

[Pharmacologic myocardial protection during percutaneous transluminal coronary angioplasty (PTCA) by intracoronary dipyridamole: hemodynamic, contractile and dynamic ventricular consequences]. / Pharmakologische Myokardprotektion während perkutaner transluminaler Koronarangioplastie (PTCA) durch Dipyridamol intrakoronar: hämodynamische, kontraktile und ventrikeldynamische Konsequenzen.

Percutaneous transluminal coronary angioplasty (PTCA) represents a suitable model to establish myocardial ischemia in man. Balloon inflation usually is accompanied by a significant deterioration in left ventricular systolic and diastolic properties. A brief episode of ischemia followed by reperfusion termed preconditioning has been identified as a mechanism rendering the myocardium more resistant to ischemia. Adenosine is considered as important mediator of preconditioning. Dipyridamole represents an important drug interfering with myocardial adenosine metabolism by inhibiting its cellular reuptake. The aim of this study was to investigate if an intracoronary infusion of dipyridamole represents a suitable tool in preventing the deterioration of left ventricular performance and hemodynamics during PTCA. In 20 patients undergoing elective coronary angioplasty of a major vessel assessment of angiographic left ventricular performance and left ventricular hemodynamics was performed before, during and after coronary angioplasty. Patients were randomly allocated to study group 1 receiving an intracoronary infusion of dipyridamole prior to PTCA and study group 2 where conventional pretreatment was performed. In study group 3 intracoronary dipyridamole infusion was performed in 10 patients with coronary artery disease during coronary angiography in order to evaluate its effect on baseline hemodynamics and left ventricular performance. Dipyridamole-pretreatment resulted in a significant preservation of systolic and diastolic left ventricular performance during PTCA, as documented by an uneffected global ejection fraction (in comparison to a deterioration of 29.2% in study group 2) and an increment in diastolic stiffness of only 12.7% (in comparison to an increment of 57.3% in study group 2). Furthermore, a significant prolongation of achievable balloon-inflation times of 48.4% could be obtained in study group 1. In addition, incidence of arrhythmias seemed to be reduced in study group 1. Apart from two cases of coronary steal phenomenon no significant side effects of dipyridamole infusion could be detected. Finally, in study group 3 dipyridamole-pretreatment per se induced a significant amelioration of angiographically assessed left ventricular systolic performance.(ABSTRACT TRUNCATED AT 400 WORDS)