The use of the acute Pd/Pa drop after intracoronary nitroglycerin infusion to rule out significant FFR: CANICA (Can intracoronary nitroglycerin predict fractional flow reserve without adenosine?) multicenter study.

OBJECTIVE: Functional assessment of coronary artery stenosis is performed by measuring the fractional flow reserve (FFR) under hyperemic conditions (Adenosine). However, the use of adenosine portends limitations. OBJECTIVE: We sought to investigate the relationship and correlation between FFR and the Pd/Pa value obtained just after the intracoronary infusion (acute drop) of nitroglycerin (Pd/Pa-NTG) and if this parameter enhances diagnostic accuracy for FFR prediction compared to the resting baseline Pd/Pa. METHODS: We conducted a multicenter study including prospectively patients presenting intermediate coronary artery stenosis (30-70%) evaluated with pressure wire. Resting baseline Pd/Pa, Pd/Pa-NTG and FFR were measured. RESULTS: 283 patients (335 lesions) were included. Resting baseline Pd/Pa value was 0.72 to 1.0 (0.93 ± 0.04), Pd/Pa-NTG was 0.60 to 1.0 (0.87 ± 0.07) and FFR 0.55 to 1.0 (0.83 ± 0.08). The ROC curves for resting baseline Pd/Pa and for Pd/Pa-NTG, using a FFR ≤ 0.80 showed an AUC of 0.88 (95% CI: 0.84-0.92, P < 0.001) and 0.94 (95% CI: 0.92-0.96, P < 0.001) respectively. The optimal cutoff values of resting baseline Pd/Pa and Pd/Pa-NTG for an FFR > 0.80, were >0.96 and >0.88, respectively. These values were present in a 29.8% (n = 100) and a 47.1% (n = 158), of the total lesions. Scatter plots showed a better correlation and agreement points with Pd/Pa-NTG than resting baseline Pd/Pa. The cutoff value of Pd/Pa-NTG > 0.88 showed an excellent NPV (96.2% for FFR > 0.8 and 100% for FFR > 0.75) and sensitivity (95% for FFR > 0.8 and 100% for FFR > 0.75) which were consistently high across all the subgroups analysis. CONCLUSION: The cutoff value of acute Pd/Pa-NTG > 0.88 has a high NPV meaning adenosine-FFR can be avoided in almost half of lesions.

Prospective registry of symptomatic severe aortic stenosis in octogenarians: a need for intervention.

OBJECTIVE: To study the factors associated with choice of therapy and prognosis in octogenarians with severe symptomatic aortic stenosis (AS). STUDY DESIGN: Prospective, observational, multicenter registry. Centralized follow-up included survival status and, if possible, mode of death and Katz index. SETTING: Transnational registry in Spain. SUBJECTS: We included 928 patients aged ≥80 years with severe symptomatic AS. INTERVENTIONS: Aortic-valve replacement (AVR), transcatheter aortic-valve implantation (TAVI) or conservative therapy. MAIN OUTCOME MEASURES: All-cause death. RESULTS: Mean age was 84.2 ± 3.5 years, and only 49.0% were independent (Katz index A). The most frequent planned management was conservative therapy in 423 (46%) patients, followed by TAVI in 261 (28%) and AVR in 244 (26%). The main reason against recommending AVR in 684 patients was high surgical risk [322 (47.1%)], other medical motives [193 (28.2%)], patient refusal [134 (19.6%)] and family refusal in the case of incompetent patients [35 (5.1%)]. The mean time from treatment decision to AVR was 4.8 ± 4.6 months and to TAVI 2.1 ± 3.2 months, P < 0.001. During follow-up (11.2-38.9 months), 357 patients (38.5%) died. Survival rates at 6, 12, 18 and 24 months were 81.8%, 72.6%, 64.1% and 57.3%, respectively. Planned intervention, adjusted for multiple propensity score, was associated with lower mortality when compared with planned conservative treatment: TAVI Hazard ratio (HR) 0.68 (95% confidence interval [CI] 0.49-0.93; P = 0.016) and AVR HR 0.56 (95% CI 0.39-0.8; P = 0.002). CONCLUSION: Octogenarians with symptomatic severe AS are frequently managed conservatively. Planned conservative management is associated with a poor prognosis.

Determinants of inducibility of ventricular tachycardia.

We analyzed the incidence and predictive factors for induction of clinical ventricular tachycardia (VT) during an electrophysiologic study in 127 patients with structural heart disease and spontaneous VT documented by 12-lead electrocardiography. Eighty-five patients had coronary artery disease (CAD), 24 had idiopathic dilated cardiomyopathy (IDC), and 18 had right ventricular dysplasia (RVD). Clinical variables were age, gender, electrocardiographic patterns of spontaneous arrhythmia, cardiac diagnosis, left ventricular (LV) ejection fraction (EF), infarct location, and presence of LV aneurysm. Clinical VT was induced in 76 patients (60%, group 1) and was not induced in 51 patients (group 2). Clinical VT was induced in 83% of patients with RVD, 58% of patients with CAD, and 50% of patients with IDC (p = 0.07). LVEF tended to be significantly higher in group 1 than in group 2 (p = 0.06). The presence of left QRS axis in the frontal plane during spontaneous VT was significantly associated with a higher inducibility both in the general group (69% vs 46%, p <0.02) and in patients with CAD (70% vs 44%, p <0.02). In patients with CAD, only the presence of a left QRS axis was significantly associated with a higher inducibility. A multivariate analysis identified only the left QRS axis as a significant and independent predictor of induction of clinical VT. The association of a leftward axis with inducibility suggests that vectorial factors in the depolarization wavefronts may be related to inducibility since conventional stimulation is performed from the right ventricle, producing a leftward axis in most cases.

[Electric treatment of atrial fibrillation]. / Tratamiento eléctrico de la fibrilación auricular.

In the present manuscript the information concerning electrical therapy of atrial fibrillation (AF) to prevent its development and to control its consequences (excluding ablation which will be covered in separate manuscripts of this series) is reviewed. Both presently conventional approaches and those undergoing investigation will be considered, under three general headings. Electrical stimulation to prevent the development of AF. Based on non controlled studies comparing VVI stimulation with other modalities that include stimulation of the atria, it was suggested that atrial stimulation could prevent AF recurrences in patients with sinus node dysfunction. This concept has been questioned in recent studies. In contrast, the hypothesis that specific ways of atrial stimulation (stimulation at sites other than the high right atrium, multisite simultaneous or with certain "delays" atrial stimulation) may be more efficacious is presently under enthusiastic assessment. Electrical stimulation to control ventricular response. Despite the evidence that ventricular stimulation may contribute to regularization and rate control during AF, its quantitative value seems to be scarce and, thus, is not of regular use in practice. Automatic implantable atrial defibrillator. Both animal experiments and clinical studies have demonstrated that the atria can be defibrillated using intracavitary electrodes with less than 3 joules in most cases, and without risk of inducing ventricular tachyarrhythmias as long as shocks are synchronized to the R wave and the preceding R-R interval is not short. Although an implantable atrial defibrillator is already undergoing clinical evaluation, the subject of tolerability of patients to shocks for non malignant arrhythmias is still controversial, since even low energy shocks seem to be painful.

[Feasibility and safety of intracoronary ultrasound. Experience of a single center]. / Viabilidad y seguridad del empleo de la ecografía intracoronaria. Experiencia de un centro.

BACKGROUND AND OBJECTIVES: Intracoronary ultrasound provides a number of advantages in the quantification and characterization of coronary stenoses with regard to contrast angiography. However, previous studies have reported a 3.5 to 11% complication rate, and a 10-30% failure rate in performing this technique. The purpose of the study is to analyze the feasibility of performing intracoronary ultrasound and the incidence of complications associated with the use of contemporary, state of the art equipment. MATERIAL AND METHODS: The feasibility of performing intracoronary ultrasound, analyzed as the percentage of successes and failures in performing the examination was reviewed, as well as the complication rate associated with the technique in all the procedures carried out between July 1, 1994 and February 29, 1996 in which intravascular ultrasound was attempted. Complications were categorized as related, non-related and uncertainly related to the ultrasound study. RESULTS: 239 vessels were studied with intravascular ultrasound in 209 procedures (74% interventional) performed on 139 patients. Ultrasound examination was feasible in all the diagnostic studies and in 96% of the interventional procedures. The major and minor procedural complication rate was 2.4 and 10.5% respectively. No major complication was related to the ultrasound examination. Three patients experienced minor complications (1.4%) related to the ultrasound study. All three complications occurred in baseline studies during interventional procedures. CONCLUSIONS: Intracoronary ultrasound is feasible and safe in the vast majority of the procedures. Improvements in smaller catheter size and design and larger operator expertise have significantly reduced the complication rate, particularly the most frequent coronary spasm so far. Complications are associated with baseline studies during interventional procedures and with less operator expertise.

[Mechanism and location of typical atrial flutter. Information drawn from experimental models and clinical electrophysiology]. / Mecanismo y localización del flutter auricular típico. Información obtenida de los modelos experimentales y de la electrofisiología clínica.

Several experimental models have been proposed to explain the electrocardiographic and electrophysiological characteristics of atrial flutter. In animal models based on anatomical obstacles, intercaval crush or Y like shaped lesion located in the right atrium, it has been possible to induce sustained atrial arrhythmias in which the entrainment criteria could be demonstrated. Additionally these tachycardias presented an atrialwave morphology similar to the F waves of type 1 or typical atrial flutter. Flutter type 2 could better be explained by models based on functional reentry like the leading circle. Typical atrial flutter in human, saw teeth morphology in inferior ECG leads, is though to be a circus movement located in the right atrium, as deduced of the analysis of activation sequence, resetting and entrainment phenomena from right and left atrium. Moreover the successful results of RDF ablation procedures confirm this idea. Nevertheless the delimitation of the anatomical boundaries of the reentry pathway remains inconclusive.

[Subacute thrombosis with antiplatelet treatment in a non-selected population of intracoronary stents: incidence and predictors]. / Trombosis subaguda con tratamiento antiagregante en una población no seleccionada de stents intracoronarios: incidencia y predictores.

INTRODUCTION: After coronary stenting, the incidence of subacute stent thrombosis have been reduced to 0% using aspirin and ticlopidine, in studies with selected populations and intracoronary ultrasounds. OBJECTIVE: To evaluate the incidence and predictors of subacute stent thrombosis in a nonselected population, using antithrombotic therapy. METHODS: We studied 285 stents, consecutively and successfully implanted in 268 lesions of 226 patients. We used high pressure balloon inflation without intracoronary ultrasound. Post-stenting protocol included aspirin and ticlopidine during four weeks with no anticoagulation. We defined subacute stent thrombosis as death, acute myocardial infarction myocardial infarction or angiographic occlusion of stent, with TIMI flow 0-1, after the first 24 hours and during the first month. RESULTS: Four patients presented events (1.7%): Three nonfatal myocardial infarction after discharge, with documented angiographic thrombosis of stent, and one death due to in-hospital myocardial infarction. All three non-fatal AMI, occurred in vessels less than 3 mm (p = 0.07) and in patients taking aspirin without ticlopidine (p < 0.001). After discharge, three (17%) of 18 patients with inadvertent discontinuation of ticlopidine presented subacute stent thrombosis, in contrast to none of 25 patients taking ticlopidine without aspirin. Excluded patients with discontinuation of ticlopidine, the incidence of subacute stent thrombosis was 0.5%. CONCLUSION: After intracoronary stenting in a nonselected population, using antithrombotic treatment with aspirin and ticlopidine, we may expect a rate of subacute stent thrombosis about 1%. Ticlopidine seems to have the main role in preventing subacute stent thrombosis, above all in predisposing circumstances as small vessels.

[Usefulness of predictors of angiographic restenosis to predict clinical restenosis after coronary stent placement]. / Utilidad de los predictores de reestenosis angiográfica en la predicción de reestenosis clínica de stents intracoronarios.

INTRODUCTION: After coronary stenting, several predictors of angiographic in-stent restenosis have been identified in different studies, however, little is known about predictors of clinical restenosis, a more functional aspect of coronary restenosis. AIM: To assess whether risk factors for angiographic restenosis previously described, are able to predict clinical restenosis and at what rate in current practice. PATIENTS AND METHODS: 216 consecutive patients (271 stents in 256 lesions) with procedural success were followed-up for 17.6 +/-10 months during periodic visits. Clinical restenosis was defined as the presence of symptoms or signs of myocardial ischemia, associated with >= 50% diameter stenosis on the angiogram. RESULTS: Clinical restenosis occurred in 33 lesions (13%), which were revascularized with 34 stents associated with unstable angina in 29, acute myocardial infarction in three and death in one case. Multivariate analysis identified as independent predictors of clinical restenosis, a vessel diameter less than 3 mm (p < 0.001, OR 4.5), a restenotic lesion (p = 0.01, OR 2.9) and the presence of residual stenosis by visual estimate (> 0%) after implantation (p = 0. 02, OR 2.5). These three risk factors explained most clinical restenosis (73%), with rates of 22% when at least one was present and 4% in absence of all these. The presence of diabetes mellitus, the location in the anterior descending coronary artery or at coronary ostium, and the number or total length of stents per lesion did not achieve an independent, significant association as predictors of clinical restenosis. CONCLUSIONS: Most clinical restenosis after coronary stenting can be predicted by the restenotic character of the revascularized lesion, the diameter of the vessel being less than 3 mm and the presence of residual stenosis by visual estimate at the end of procedure.

In-hospital outcome of elderly patients with acute inferior myocardial infarction and right ventricular involvement.

BACKGROUND: There are some specific high-risk subgroups of patients with acute inferior myocardial infarction, such as older patients and those with right ventricular involvement. However, the clinical implications of right ventricular infarction in elderly subjects have not been studied previously. METHODS AND RESULTS: To determine the clinical impact of right ventricular involvement in elderly patients with inferior myocardial infarction, we studied the in-hospital outcome of 198 consecutive patients > or = 75 years of age with a first acute inferior myocardial infarction according to the presence of ECG or echocardiographic criteria of right ventricular infarction. In patients with right ventricular involvement (41%), in-hospital case fatality rate was 47% (mainly because of nonreversible low cardiac output cardiogenic shock) compared with 10% in patients without right ventricular involvement (P<.001). Patients with right ventricular involvement also had a significantly higher incidence of cardiogenic shock (32% versus 5%), which was independent of left ventricular ejection fraction, complete AV block (33% versus 9%), and interventricular septal rupture (9% versus 0%). After adjustment for age, sex, diabetes, shock on admission, left ventricular systolic dysfunction, and complete AV block, right ventricular infarction remained a powerful independent predictor of in-hospital death (adjusted odds ratio, 4.0; 95% confidence interval, 1.3 to 14.2). CONCLUSIONS: Elderly patients with acute inferior myocardial infarction have a substantially increased risk of death during hospitalization when right ventricular involvement is present. The poorer outcome is due mainly to the high incidence of cardiogenic shock and its infrequent reversibility.

Combined effect of age and right ventricular involvement on acute inferior myocardial infarction prognosis.

BACKGROUND: In patients with acute inferior myocardial infarction (AIMI), right ventricular involvement (RVI) is one of the strongest predictors of in-hospital death. We hypothesized that the impact of RVI on AIMI prognosis depends on the patient's age. METHODS AND RESULTS: The in-hospital clinical outcome of 798 consecutive patients admitted to the coronary care unit within 48 hours of symptom onset with AIMI was analyzed according to patient age and to the presence of RVI diagnosed by ECG and/or echocardiographic criteria. The total incidence of RVI was 37%, and it increased as age advanced. Patients with RVI had a significantly higher incidence of major complications (45% versus 19%, P<0.0001) and a higher in-hospital mortality rate (22% versus 6%, P<0.0001). The prognostic effect of RVI was independent of sex, smoking, diabetes, shock on admission, left ventricular ejection fraction, and reperfusion therapy, all age-dependent predictors. A multivariate analysis showed a significant (P=0.03) interaction between age and RVI on AIMI mortality. RVI increased mortality risk only in the oldest patients. CONCLUSIONS: In patients with AIMI, RVI substantially increases mortality risk in elderly patients, whereas it has a nonsignificant effect in young subjects.