Luminal narrowing after percutaneous transluminal coronary angioplasty. A study of clinical, procedural, and lesional factors related to longterm angiographic outcome

Background. The renarrowing process after successful percutaneous transluminal coronary angioplasty (PTCA) is now believed to be caused by a response-to-injury vessel wall reaction. The magnitude of this process can be assessed by the change in minimal lumen diameter (MLD) at follow-up angiography. The aim of the present study was to find independent patient-related, lesion-related, and procedure-related risk factors for this luminal narrowing process. A model that accurately predicts the amount of luminal narrowing could be an aid in patient or lesion selection for the procedure, and it could improve assessment of medium-term (6 months) prognosis. Modification or control of the identified risk factors could reduce overall restenosis rates, and it could assist in the selection of patients at risk for a large loss in lumen diameter. This population could then constitute the target population for pharmacological intervention studies. Methods and Results. Quantitative angiography was performed on 666 successfully dilated lesions at angioplasty and at 6-month follow-up. Multivaria

Directional atherectomy for treatment of restenosis within coronary stents: clinical, angiographic and histologic results

Abstract OBJECTIVES: The safety and long-term results of directional coronary atherectomy in stented coronary arteries were determined. In addition, tissue studies were performed to characterize the development of restenosis. METHODS: Directional coronary atherectomy was performed in restenosed stents in nine patients (10 procedures) 82 to 1,179 days after stenting. The tissue was assessed for histologic features of restenosis, smooth muscle cell phenotype, markers of cell proliferation and cell density. A control (no stenting) group consisted of 13 patients treated with directional coronary atherectomy for restenosis 14 to 597 days after coronary angioplasty, directional coronary atherectomy or laser intervention. RESULTS: Directional coronary atherectomy procedures within the stent were technically successful with results similar to those of the initial stenting procedure (2.31 +/- 0.38 vs. 2.44 +/- 0.35 mm). Of five patients with angiographic follow-up, three had restenosis requiring reintervention (surgery in two and repeat atherectomy followed by laser angioplasty in one). Intimal hyperplasia was identified in 80% of specimens after stenting and in 77% after coronary angioplasty or atherectomy. In three patients with stenting, 70% to 76% of the intimal cells showed morphologic features of a contractile phenotype by electron microscopy 47 to 185 days after coronary intervention. Evidence of ongoing proliferation (proliferating cell nuclear antigen antibody studies) was absent in all specimens studied. Although wide individual variability was present in the maximal cell density of the intimal hyperplasia, there was a trend toward a reduction in cell density over time. CONCLUSIONS: Although atherectomy is feasible for the treatment of restenosis in stented coronary arteries and initial results are excellent, recurrence of restenosis is common. Intimal hyperplasia is a nonspecific response to injury regardless of the device used and accounts for about 80% of cases of restenosis. Smooth muscle cell proliferation and phenotypic modulation toward a contractile phenotype are early events and largely completed by the time of clinical presentation of restenosis. Restenotic lesions may be predominantly cellular, matrix or a combination at a particular time after a coronary procedure

Usefulness of quantitative and qualitative angiographic lesion morphology, and clinical characteristics in predicting major adverse cardiac events during and after native coronary balloon angioplasty

Major, adverse cardiac events (death, myocardial infarction, bypass surgery and reintervention) occur in 4 to 7% of all patients undergoing coronary balloon angioplasty. Prospectively collected clinical data, and angiographic quantitative and qualitative lesion morphologic assessment and procedural factors were examined to determine whether the occurrence of these events could be predicted. Of 1,442 patients undergoing balloon angioplasty for native primary coronary disease in 2 European multicenter trials, 69 had major, adverse cardiac procedural or in-hospital complications after ≥1 balloon inflation and were randomly matched with patients who completed an uncomplicated in-hospital course after successful angioplasty. No quantitative angiographic variable was associated with major adverse cardiac events in univariate and multivariate analyses. Univariate analysis showed that major adverse cardiac events were associated with the following preprocedural variables: (1) unstable angina (odds ratio [OR] 3.11; p 45 ° (OR 2.34; p 45 ° (OR 2.87; p 45 ° (OR 2.54; p < 0.006) were independent predictors of major adverse cardiac events

Randomized trial of a GPIIb/IIIa platelet receptor blocker in refractory unstable angina

BACKGROUND: Patients with unstable angina despite intensive medical therapy, ie, refractory angina, are at high risk for developing thrombotic complications: myocardial infarction or coronary occlusion during percutaneous transluminal coronary angioplasty (PTCA). Chimeric 7E3 (c7E3) Fab is an antibody fragment that blocks the platelet glycoprotein (GP) IIb/IIIa receptor and potently inhibits platelet aggregation. METHODS AND RESULTS: To evaluate whether potent platelet inhibition could reduce these complications, 60 patients with dynamic ST-T changes and recurrent pain despite intensive medical therapy were randomized to c7E3 Fab or placebo. After initial angiography had demonstrated a culprit lesion suitable for PTCA, placebo or c7E3 Fab was administered as 0.25 mg/kg bolus injection followed by 10 micrograms/min for 18 to 24 hours until 1 hour after completion of second angiography and PTCA. During study drug infusion, ischemia occurred in 9 c7E3 Fab and 16 placebo patients (P = .06). During hospital stay, 12 major events occurred in 7 placebo patients (23%), including 1 death, 4 infarcts, and 7 urgent interventions. In the c7E3 Fab group, only 1 event (an infarct) occurred (3%, P = .03). Angiography showed improved TIMI flow in 4 placebo and 6 c7E3 Fab patients and worsening of flow in 3 placebo patients but in none of the c7E3 Fab patients. Quantitative analysis showed significant improvement of the lesion in the patients treated with c7E3 Fab, which was not observed in the placebo group, although the difference between the two treatment groups was not significant. Measurement of platelet function and bleeding time demonstrated > 90% blockade of GPIIb/IIIa receptors, > 90% reduction of ex vivo platelet aggregation to ADP, and a significantly prolonged bleeding time during c7E3 Fab infusion, without excess bleeding. CONCLUSIONS: Combined therapy with c7E3 Fab, heparin, and aspirin appears safe. These pilot study results support the concept that effective blockade of the platelet GPIIb/IIIa receptors can reduce myocardial infarction and facilitate PTCA in patients with refractory unstable angina

La serendipia en torno la fracción de eyección: una revisión de la historia, la casualidad y la cuasi-funcionalidad de una métrica aplaudida

Ejection fraction (EF) is defined by the ratio of end-systolic volume (ESV) and end-diastolic volume (EDV). The resulting fraction is a dimensionless number, rendering the interpretation of EF ambiguous and possibly misleading. Notwithstanding these serious limitations, it is remarkable to observe that the metric EF gained wide acceptance as a clinical marker of cardiac function. In this survey we reconcile the role of the fundamental determinant of ventricular mechanics, namely ESV, with the theoretically unexpected yet universal popularity of EF. Underlying trivial mathematics, as based on physiology, explain a rather straightforward association between EF and ESV. This concept is illustrated by detailed analysis of patient data derived from angiocardiography, echocardiography and CMR. EF versus ESV yields a nonlinear curve. For small ESV the EF approaches 100%, while for very large ESV the EF gradually declines towards zero. Such a plain relationship is generally observed in natural (innervated) hearts. Thus, the glorified popularity of EF mostly derives from the fortuitous connection with the pivotal variable ESV. Alongside this finding we unfold various historical developments that facilitated the emergence of EF as a product of serendipity. Our insightful approach is founded on physiology and denounces circumstantial theories that were invoked by other researchers when justifying the importance of EF as an index of cardiac function. Here, several of these theories are critically discussed, while pinpointing their flaws. In conclusion we propose ESV as a more logical metric to analyze ventricular function. EF appears to be no more than a blessing in disguise

Pressure-derived fractional flow reserve to assess serial epicardial stenoses : theoretical basis and animal validation

Background: Fractional flow reserve (FFR) is an index of stenosis severity validated for isolated stenoses. This study develops the theoretical basis and experimentally validates equations for predicting FFR of sequential stenoses separately. Methods and Results: For 2 stenoses in series, equations were derived to predict FFR (FFRpred) of each stenosis separately (ie, as if the other one were removed) from arterial pressure (Pa), pressure between the 2 stenoses (Pm), distal coronary pressure (Pd), and coronary occlusive pressure (Pw). In 5 dogs with 2 stenoses of varying severity in the left circumflex coronary artery, FFRpred was compared with FFRapp (ratio of the pressure just distal to that just proximal to each stenoses) and to FFRtrue (ratio of the pressures distal to proximal to each stenosis but after removal of the other one) in case of fixed distal and varying proximal stenoses (n=15) and in case of fixed proximal and varying distal stenoses (n=20). The overestimation of FFRtrue by FFRapp was larger than that of FFRtrue by FFRpred (0.070±0.007 versus 0.029±0.004,

Pressure-derived fractional flow reserve to assess serial epicardial stenoses : theoretical basis and animal validation

Background: Fractional flow reserve (FFR) is an index of stenosis severity validated for isolated stenoses. This study develops the theoretical basis and experimentally validates equations for predicting FFR of sequential stenoses separately. Methods and Results: For 2 stenoses in series, equations were derived to predict FFR (FFRpred) of each stenosis separately (ie, as if the other one were removed) from arterial pressure (Pa), pressure between the 2 stenoses (Pm), distal coronary pressure (Pd), and coronary occlusive pressure (Pw). In 5 dogs with 2 stenoses of varying severity in the left circumflex coronary artery, FFRpred was compared with FFRapp (ratio of the pressure just distal to that just proximal to each stenoses) and to FFRtrue (ratio of the pressures distal to proximal to each stenosis but after removal of the other one) in case of fixed distal and varying proximal stenoses (n=15) and in case of fixed proximal and varying distal stenoses (n=20). The overestimation of FFRtrue by FFRapp was larger than that of FFRtrue by FFRpred (0.070±0.007 versus 0.029±0.004,