Clinical and angiographic outcomes following elective implantation of the Carbostent in patients at high risk of restenosis and target vessel failure.

The Carbostent is a new balloon-expandable, stainless steel, tubular stent with innovative multicellular design and unique turbostratic carbon coating. The aim of this study was to assess clinical and angiographic outcomes after Carbostent implantation in 112 patients poorly suitable for an effective treatment with stenting because of the high risk of thrombosis, late restenosis, and clinical target vessel failure. The inclusion criteria were age > 75 years, diabetes mellitus, a lesion length > 10 mm, a reference vessel diameter < 3.0 mm, an ostial location of the target lesion, and chronic total occlusion. Overall, a total of 175 stents ranging from 9 to 25 mm in length were placed in 147 lesions. There were no stenting attempt failures. The acute gain after stent implantation was 2.46 +/- 0.51 mm, and the residual stenosis 0 +/- 4%. No stent thrombosis occurred, nor myocardial infarction. The 6-month event-free survival rate was 74% +/- 5%. The 6-month angiographic follow-up showed a late loss of 0.81 +/- 0.88 mm and a binary (> or = 50%) restenosis rate of 25%. The results of this study suggest that the Carbostent may be highly effective in patients at high risk of restenosis and target vessel failure.

Direct infarct artery stenting without predilation and no-reflow in patients with acute myocardial infarction.

BACKGROUND: In patients with acute myocardial infarction (AMI), the rate of microvascular embolization and no-reflow promoted by coronary stenting with the use of conventional techniques (CS) appears to be greater than the one that occurs with balloon angioplasty. The minor invasiveness of direct stenting (DS) of the infarct artery without predilation could be expected to reduce embolization in the coronary microvasculature and no-reflow in patients with AMI. METHODS: In a cohort of 423 consecutive patients with AMI who underwent infarct-artery stenting, we compared CS and DS in terms of angiographic no-reflow rate and 1-month clinical outcome. RESULTS: At baseline patients who underwent DS (n = 110) had a better risk profile compared with the use of CS (n = 313). The incidence of angiographic no-reflow was 12% in the CS group and 5.5% in the DS group (P =.040). The 1-month mortality rate was 8% in the CS group and 1% in the DS group (P =.008). The mortality rate was 11% in patients with no-reflow and 5.6% in patients with a normal flow. Multivariate analysis showed that age, preprocedure patent infarct artery, and lesion length were related to the risk of no-reflow. In the subset of patients with a target lesion length

Sex-based differences in clinical and angiographic outcomes after primary angioplasty or stenting for acute myocardial infarction.

A paucity of data exists on the importance of gender in contributing to the mortality rate after primary angioplasty, although it is has been shown that women with acute myocardial infarction (AMI) are less likely than men to undergo reperfusion treatments. This study analyzes gender-related differences in 6-month clinical and angiographic outcomes in nonselected patients with AMI who underwent primary angioplasty or stenting. We compared clinical and angiographic outcomes of 230 women and 789 men who underwent primary angioplasty or stenting from January 1995 to August 1999. The women were older than the men, and had a greater incidence of diabetes and cardiogenic shock. The 6-month mortality rate was 12% in women and 7% in men (p = 0.028). Nonfatal reinfarction occurred in 3% of the women and in 1% of the men (p = 0.010). There were no differences in repeat target vessel revascularization rates. After multivariate analysis, gender did not emerge as a significant variable in relation to 6-month mortality or to the combined end point of death, reinfarction, and repeat target vessel revascularization. Both women and men with stented infarct arteries had lower restenosis rates (29% and 26%, respectively) than patients without stents (52% and 39%, repectively). The results of outcome analysis in nonselected patients suggest that sex is not an independent predictor of mortality after primary angioplasty for AMI, and that the benefit of primary stenting is similar in men and women.

Primary stenting in nonselected patients with acute myocardial infarction: the Multilink Duet in Acute Myocardial Infarction (MIAMI) trial.

Most randomized trials comparing primary stenting with primary coronary angioplasty (PTCA) excluded patients at high risk from enrollment, thus arising the important question about the generalizability of the randomized trial results to all patients with AMI. The aim of this study was to assess the feasibility and effectiveness of a primary infarct-related artery (IRA) stenting strategy using a second-generation tubular stent in nonselected patients with acute myocardial infarction (AMI). All patients with AMI were considered eligible for primary IRA stenting. No restriction was made based on age or clinical status on presentation, or coronary anatomy, except in cases of a reference IRA diameter < 2.5 mm. The primary endpoint of the study was clinical target vessel failure defined as death, reinfarction, or repeat TVR due to restenosis or reocclusion of the IRA. Between June 1998 and March 1999, 201 consecutive patients with AMI underwent mechanical recanalization of the IRA. The mean age was 64 +/- 12, and 16% of patients were aged 75 years or over. The incidence of shock was 9%. Primary IRA stenting was performed in 89% of the patients. Patients who underwent PTCA alone had a smaller IRA diameter as compared to patients with a stented IRA (2.48 +/- 0.46 mm vs. 3.15 +/- 0.37 mm; P < 0.001). There were no stent deployment failures. The 6-month primary endpoint rate was 15% (2 deaths, 27 repeat TVR, 0 reinfarctions), while the 6-month angiographic restenosis rate was 22%. Primary IRA stenting in nonselected patients with AMI is highly feasible and associated with favorable clinical and angiographic outcomes. Cathet. Cardiovasc. Intervent. 51:273-279, 2000.

Clinical and angiographic outcome after coronary arterial stenting with the carbostent.

The Carbostent is a new balloon-expandable, stainless steel, tubular stent with innovative multicellular design and unique turbastratic carbon coating (Carbofilm). This open nonrandomized 2-center study assesses the immediate and long-term clinical and angiographic outcomes after Carbostent implantation in patients with native coronary artery disease. The Carbostent was implanted in 112 patients with 132 de novo lesions. Most patients (55%) had unstable angina, and 38% of lesions were type B2-C. The mean lesion length was 12.5 +/- 7.0 mm, and 29% of lesions were > 15 mm in length. No stent deployment failure occurred, as well as acute or sub-acute stent thrombosis. The 6-month event-free survival was 84 +/- 4%. One patient with a stented right coronary artery and no restenosis at the angiographic follow-up died after 6 months of fatal infarction due to abrupt closure of a nontarget vessel. In-hospital non-Q-wave myocardial infarction occurred in 1 patient, and 11 patients had repeat target lesion revascularization (target lesion revascularization rate 10%). The 6-month angiographic follow-up was obtained in 108 patients (96%) (127 lesions). Angiographic restenosis rate was 11%. The loss index was 0.29 +/- 0.28. The results of this study indicate a potential benefit of Carbostent for the prevention of stent thrombosis and restenosis in these relatively high-risk patients. A larger trial is being planned to confirm these promising results.

Stenting for in-stent restenosis.

Intravascular ultrasound studies have shown that additional stent implantation is the only percutaneous technique that allows for recovery of all the lumen area of the original implantation procedure. Despite this theoretical advantage, information on systematic additional stent implantation is still forthcoming, especially concerning the impact of new stent designs. This prospective study evaluated the efficacy of routine additional stent implantation for treatment of in-stent restenosis in 68 consecutive patients. Repeat stenting was successful in all cases, and second-generation tubular stents were used in 84% of patients. The mean additional stent length was 19.2 +/- 9.4 mm, and 15% of patients had multiple stent implantation. The postprocedure minimum lumen diameter was 3.11 +/- 0.41 mm, and the percentage residual stenosis was 2% +/- 7%. At a mean clinical follow-up of 10 +/- 8 months (follow-up rate 100%), the incidence of major adverse events was 21% (1 death, 13 target vessel revascularizations). Overall, angiographic restenosis rate was 32% (angiographic follow-up rate 79%). By multivariate analysis, the only predictors of recurrence after additional stenting were unstable angina at the second procedure (OR 8.70, 95% CI 1.50-50.33, P = 0.019), and early clinical recurrence after the first stent procedure (OR 4.83, 95% CI 1.13-20.71, P = 0.038). Additional stenting is a safe and effective treatment modality for the majority of patients with in-stent restenosis. Alternative treatments should be considered only for patients with in-stent restenosis presenting as unstable angina or early recurrence after a first stent procedure.

Efficacy of a "stent-like" PTCA strategy in current clinical practice.

Retrospective analysis within the BENESTENT-l trial has shown that patients having a "stent-like" result after standard PTCA had angiographic and clinical outcomes similar to those of patients receiving a stent. The objective of this study is to assess the efficacy of a "stent-like" PTCA strategy in native coronary arteries in non-selected patients. From our data base, 503 consecutive patients who underwent successful PTCA or stent supported PTCA were stratified according to a target lesion length < 15 mm, a reference vessel diameter > or = 2.5 mm, and a postprocedural residual stenosis < 30%. After stratification, 132 patients with "stent-like" PTCA, and 88 with single stent implantation were compared on two-year clinical outcomes. Two-year event-free survival rate was 70% in the "stent-like" PTCA group, and 83% in the stent group (p = 0.022). Stent-like PTCA is associated with a higher restenosis rate and higher adverse events rate as compared to single stent supported PTCA, whatever the indication for stenting.

Primary coronary infarct artery stenting in acute myocardial infarction.

Completed and ongoing randomized trials have provided results that favor primary infarct-related artery (IRA) stenting as opposed to primary percutaneous transluminal coronary angioplasty, but the applicability of the trial results to all patients with acute myocardial infarction (AMI) has not yet been investigated. This study sought to determine the applicability of an unconditional IRA stenting strategy in nonselected patients with AMI. After successful mechanical recanalization of the IRA, all patients with AMI and a reference diameter > or =2.5 mm were considered eligible for primary IRA stenting without any restriction regarding age or clinical status on presentation. The primary end point of the study was a composite end point defined as death, reinfarction, or repeat target lesion revascularization. Primary IRA stenting was successfully performed in 161 of 190 consecutive patients with AMI (85%), and of 162 (99%) considered suitable for stenting. Patients with nonstented IRA had a reference IRA diameter smaller than patients with a stent (2.71+/-0.48 vs 3.20+/-0.41 mm, p <0.001). Overall, the 6-month mortality was 5%. Mortality was 2% for patients without, and 32% for patients with cardiogenic shock. The incidences of reinfarction and of repeat target lesion revascularization were 1% and 12%, respectively. The 6-month angiographic follow-up showed an IRA patency rate of 94% and a restenosis rate of 26%. The results of this study strengthen the hypothesis that unconditional primary IRA stenting is highly feasible, and may actually improve the outcome of patients with AMI.

Systematic primary angioplasty in octogenarian and older patients.

BACKGROUND: There are conflicting data about the efficacy of aggressive treatment and early intervention among high-risk patients with acute myocardial infarction (AMI), such as elderly patients. This study sought to determine the short- and long-term outcome of octogenarian and older patients after primary percutaneous transluminal coronary angioplasty (PTCA). METHODS: In our tertiary referral center a program of primary PTCA was begun in 1995, and the systematic care for AMI included primary PTCA in all patients with AMI, with no age restriction. Over a period of 3 years, 55 octogenarian or older patients underwent primary PTCA. RESULTS: Between January 1995 and July 1998, 719 patients with AMI underwent primary PTCA. Of these, 55 patients were octogenarians or older (mean age, 84 +/- 3 years). Primary PTCA failure occurred in 3 (5%) patients. An optimal acute angiographic result was achieved in 51 (93%) patients. Stenting of the infarct vessel was accomplished in 33 (60%) patients. The 30-day mortality rate was 16%. The mortality rate was 4% in patients without cardiogenic shock on presentation and 70% in patients with cardiogenic shock. The recurrent ischemia rate was 13% and resulted in nonfatal reinfarction in 2 patients and repeat PTCA in 5 patients. As determined by multivariate analysis, an optimal acute angiographic result and cardiogenic shock were significantly related to mortality. The 1-year survival rate was 77%. CONCLUSIONS: The results of this study suggest that the benefits of primary PTCA apply to the very elderly and support an early aggressive strategy for this high-risk patient subset.

Current role of stenting in acute myocardial infarction.

Primary infarct artery stenting has the potential to advance treatment of acute myocardial infarction. The postulated mechanisms of the benefit of stenting in acute myocardial infarction are the achievement of an acute optimal angiographic result and correction of any residual dissection to decrease the incidence of early and late restenosis and reocclusion and of the correlated events such as fatal and nonfatal reinfarction and repeat target vessel revascularization for recurrent ischemia. The results of 5 completed randomized trials comparing primary stenting with primary percutaneous transluminal coronary angioplasty show a lower incidence of the composite end point of death, myocardial infarction, and repeat target vessel revascularization in the stent groups as compared with the angioplasty groups and support the more extensive use of stents in patients with acute myocardial infarction. The efforts of the next years will be focused on further refinement of stent design and composition and the evaluation of pharmacological agents effective in restoring myocardial reperfusion to the fullest extent.

Effectiveness of in-ward management of femoral access after invasive procedures using large sheaths.

BACKGROUND: The cost-effectiveness of expensive suture mediation devices for the management of femoral access is currently under investigation, while the effectiveness of in-ward femoral access management by standard care has not yet been assessed. METHODS: To determine whether a logistic model that includes management of femoral access by the cardiology ward staff is effective, 945 consecutive invasive procedures using > or = 8 Fr sheaths were prospectively screened over a 6-month study period. Vascular complications included: any need for surgical or endovascular repair, ultrasound-guided compression, any femoral or iliac bleeding requiring blood transfusion. RESULTS: During the study period there were 581 diagnostic procedures, and 364 interventional procedures. Interventional procedures included 98 primary PTCA, 42 coronary atherectomies, and 39 intraaortic balloon pump supported PTCA. Vascular complication rate was 1.6% (surgical repair 0.2%, ultrasound-guided compression 1.1%, blood transfusion 0.3%). CONCLUSIONS: The vascular access management by the cardiology ward staff was associated with a very low rate of vascular complications. This policy may play a role in reducing costs and improving logistics.

Doppler-derived mitral deceleration time: an early strong predictor of left ventricular remodeling after reperfused anterior acute myocardial infarction.

BACKGROUND: The relation between remodeling and left ventricular (LV) diastolic function has not yet been fully investigated. The aim of this study was to determine whether early assessment of Doppler-derived mitral deceleration time (DT), a measure of LV compliance and filling, may predict progressive LV dilation after acute myocardial infarction (AMI). METHODS AND RESULTS: Fifty-one patients (aged 61+/-11 years; 6 women) with anterior AMI successfully treated with direct coronary angioplasty underwent 2-dimensional and Doppler echocardiographic examinations within 24 hours of admission, at days 3, 7, and 30 and 6 months after the index infarction. Mitral flow velocities were obtained from the apical 4-chamber view with pulsed Doppler. End-diastolic volume index (EDVI) and end-systolic volume index (ESVI) were calculated with the Simpson's rule algorithm. Patients were divided according to the DT duration assessed at day 3 in 2 groups: group 1 (n=33) with DT >130 ms and group 2 (n=18) with DT

[Systematic treatment of acute myocardial infarction with primary angioplasty. Early clinical and angiographic results and after 6 months]. / Trattamento sistematico dell'infarto miocardico acuto con angioplastica primaria. Risultati clinici ed angiografici precoci e a sei mesi.

UNLABELLED: Starting in 1995, at our institution all patients with acute myocardial infarction (AMI) who gave informed consent were treated by primary percutaneous transluminal coronary angioplasty (PTCA) without limitations in entry criteria. This report presents early and six-month clinical and angiographic results of the 720 patients (77% male, median age 64 years) treated by direct PTCA between January 1, 1995 and July 31, 1998. On admission, 33% of patients were in Killip class > 1, and 101 patients (14%) were in early cardiogenic shock. Optimal acute angiographic success (TIMI grade 3 flow with residual stenosis < 30%) was achieved in 683 patients (95%). Primary or unplanned stenting of infarct related artery (IRA) for a suboptimal or poor angiographic result after primary PTCA was performed in 454 patients (63%). The mean time from hospital arrival to recanalization was 62 +/- 28 min. At 30 days, the mortality rate was 4.9% (1.8% in Killip class < 4 patients and 24% in patients with cardiogenic shock). The reinfarction rate was 1.2%. At 30 days, coronary angiography showed restenosis or reocclusion of the IRA in 55 patients (8.9%). During the six-month follow-up (30-180 days), there were 11 deaths (1.5%) and 2 non-fatal reinfarctions (0.3%). At six months, the IRA patency rate was 95%, while the mean ejection fraction improvement in 422 patients with paired ventriculograms was 7%. Recurrent ischemia occurred in 144 patients (20%) and resulted in 7 deaths, 11 non-fatal reinfarctions and 126 repeat targeted vessel revascularization. CONCLUSIONS: The major finding of our experience is that direct coronary angioplasty may result in excellent early and late outcome in a population without limitations in entry criteria. The low mortality and the few recurrent myocardial ischemic events are connected with the high patency rate at 6 months. The extensive use of stents improves the angiographic results and the clinical outcome.

Relation between ST-segment changes and myocardial perfusion evaluated by myocardial contrast echocardiography in patients with acute myocardial infarction treated with direct angioplasty.

The aim of this study was to evaluate the relation between myocardial perfusion and ST-segment changes in patients with acute myocardial infarction treated with successful direct angioplasty. Thirty-seven patients, successfully treated with direct angioplasty, underwent myocardial contrast echocardiography before and after angioplasty. The sum of ST-segment elevation divided by the number of the leads involved (ST-segment elevation index) was calculated at 1, 5, 10, 20, and 30 minutes after restoration of a Thrombolysis In Myocardial Infarction trial grade 3 flow. After recanalization, myocardial reperfusion within the risk area was observed in 26 patients, whereas a no-reflow phenomenon occurred in 11. In patients with myocardial reperfusion, the ST-segment elevation index progressively declined, whereas in patients with no reflow, no significant change was observed. Reduction of > or = 50% in the ST-segment elevation index occurred in 20 of the 26 patients with reflow and in 1 of the 11 with no reflow (p = 0.0002). An additional increase of > or = 30% in the ST-segment elevation index occurred in 3 patients with reflow and in 7 with no reflow (p = 0.003). Sensitivity, specificity, positive and negative predictive values, and accuracy of the reduction in the ST-segment elevation index for predicting microvascular reflow were 77%, 91%, 95%, 62%, and 81%, respectively. The corresponding values of the increase in ST-segment elevation index for predicting no reflow were 64%, 88%, 70%, 85%, and 81%, respectively. In conclusion, after successful angioplasty, different patterns of myocardial perfusion are associated with different ST-segment changes. Analysis of ST-segment changes predicts the degree of myocardial reperfusion.

[Rapid resolution of ST-segment elevation predicts functional recovery in acute myocardial infarction treated with primary percutaneous transluminal coronary angioplasty]. / La rapida riduzione del sovraslivellamento del tratto ST è predittiva del recupero della funzione nell'infarto miocardico acuto trattato con angioplastica coronarcia primaria.

OBJECTIVES: This study was designed to prospectively assess the ability of the 12-lead electrocardiogram (ECG) and optimal ECG criteria to predict late functional recovery in patients with acute myocardial infarction (AMI) treated with primary coronary angioplasty (PTCA) BACKGROUND: A simple clinical method to predict clinical outcome in patients with reperfused AMI is highly desirable from a clinical point of view. METHODS: Seventy-five patients with AMI treated with successful PTCA (TIMI flow grade 3 and residual stenosis < 30%) underwent serial 12-lead ECG before PTCA and every hour for the first 6 hours and then at 9, 12, and 18 hours after PTCA. All patients underwent two-dimensional echocardiography before PTCA and 1 and 6 months later for the evaluation of regional wall motion. The ST segment level in the lead exhibiting the maximal ST elevation (ST increase max) and the sum of the ST segment elevation (sigma ST increases) were calculated on initial ECG and a cut-off values of > or = 50% reduction of ST increases max sigma ST increases elevation and sampling intervals were correlated with late functional recovery. A wall motion score index (WMSI: 1 = normal to 4 = dyskinesia) and 16-segment model were used. Reversible dysfunction was defined as a decrease of > or = 0.22 in WMSI. RESULTS: At univariate analysis a > or = 50% reduction of both ST increases max and sigma ST increases was related to late functional recovery. Multiple logistic regression analysis revealed that reduction of sigma ST increases was the most powerful predictor of late functional recovery (p = 0.008). A > or = 50% reduction of sigma ST increase within 4 hours of PTCA provided the optimal criterion for predicting late functional recovery. CONCLUSIONS: Rapid reduction of sigma ST increases elevation is an accurate predictor of left ventricular functional recovery in patients with AMI treated with primary PTCA. Optimal criteria include a reduction in sigma ST increases elevation > or = 50% within 4 hours of PTCA.

Systematic direct angioplasty and stent-supported direct angioplasty therapy for cardiogenic shock complicating acute myocardial infarction: in-hospital and long-term survival.

OBJECTIVES: This prospective observational study was conducted to examine the apparent impact of a systematic direct percutaneous transluminal coronary angioplasty (PTCA) strategy on mortality in a series of 66 consecutive patients with acute myocardial infarction (AMI) complicated by cardiogenic shock, and to analyze the predictors of outcome after successful direct PTCA. BACKGROUND: Previous studies have reported encouraging results with PTCA in patients with AMI complicated by cardiogenic shock, but a biased case selection for PTCA may have heavily influenced the observed outcomes. METHODS: All patients admitted with AMI were considered eligible for direct PTCA, including those with the most profound shock, and no upper age limit was used. The treatment protocol also included stenting of the infarct-related artery for a poor or suboptimal angiographic result after conventional PTCA. RESULTS: Between January 1995 and March 1997, 364 consecutive patients underwent direct PTCA, and in 66 patients AMI was complicated by cardiogenic shock. In patients with cardiogenic shock, direct PTCA had a success rate of 94%; an optimal angiographic result was achieved in 85%; primary stenting of the infarct-related artery was accomplished in 47%; and the in-hospital mortality rate was 26%. Univariate analysis showed that patient age, chronic coronary occlusion and completeness of revascularization were significantly related to in-hospital mortality. The mean follow-up period was 16 +/- 8 months. Survival rate at 6 months was 71%. Comparison of event-free survival in patients with a stented or nonstented infarct-related artery suggests an initial and long-term benefit of primary stenting. CONCLUSIONS: Systematic direct PTCA, including stent-supported PTCA, can establish a Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in the great majority of patients presenting with AMI and early cardiogenic shock. High performance criteria, including new devices such as coronary stents, should be considered in randomized trials where mechanical revascularization therapy is being tested.

Acute and long-term effects of flosequinan in patients with chronic cardiac failure.

The acute and long-term effects of the orally active vasodilator flosequinan were assessed in 10 patients with New York Heart Association class II to IV cardiac failure. Baseline hemodynamics, exercise capacity, left and right ventricular ejection fraction, and pulmonary transit time were measured by right cardiac catheterization, bicycle ergometer stress testing, and nuclear angiocardiography during a run-in period on placebo. Acute hemodynamic effects of flosequinan were monitored for 48 hours; the drug was then given as a single 100 mg daily dose for 6 weeks. Exercise capacity was reevaluated every 2 weeks, and right cardiac catheterization and nuclear angiocardiography were repeated at the end of the 6-week period. Placebo did not exert any effect. Flosequinan reduced right atrial, pulmonary artery, and pulmonary artery wedge pressures from 60 minutes to 48 hours after dosing. Heart rate was minimally increased. Cardiac index, mean systemic arterial pressure, and systemic and pulmonary vascular resistance were substantially unaffected. These effects were maintained after 6 weeks. Exercise capacity was enhanced after 2, 4, and 6 weeks. Left ventricular ejection fraction was unchanged, whereas right ventricular ejection fraction and pulmonary transit time were improved. In conclusion, flosequinan exerted a potent, long-lasting, venodilating effect that was maintained long-term, without evidence of tolerance.

Age-related changes in the pharmacodynamics of intravenous glyceryl trinitrate.

Comparable hemodynamic effects were obtained administering a much lower intravenous dose of glyceryl trinitrate (GTN) in elderly than in younger patients. The pharmacodynamics and kinetics of GTN were thus assessed in 2 groups of patients with acute myocardial infarction (group A: less than or equal to 65 years, 6 patients; group B: greater than or equal to 75 years, 6 patients). The arterial and venous dose-concentration relationship and the associated hemodynamic changes at end-point (EP: 10% reduction in mean systemic arterial pressure) were similar in the 2 groups. However, in older subjects EP was reached at a lower GTN infusion rate (0.11 +/- 0.04 vs 0.33 +/- 0.11 micrograms.kg-1.min-1, mean +/- S.D.; p less than 0.001), and with lower arterial and venous drug concentrations (arterial [GTN]: 1.2 +/- 0.1 vs 4.6 +/- 1.2 ng.ml-1; p less than 0.01; venous [GTN]; 0.09 +/- 0.05 vs 0.35 +/- 0.15 ng.ml-1; p less than 0.05), whereas overall GTN kinetics appeared to be substantially independent of age. Thus, the enhanced efficacy of GTN in advanced age seems to stem mainly from pharmacodynamic changes, which may be the consequence of dampened baroreceptor reflexes, as suggested by a lower heart rate increase per unitary fall in systolic arterial pressure observed in group B (0.12 +/- 0.07 vs 0.41 +/- 0.29 b.min-1.mmHg-1; p less than 0.05).

Propafenone versus amiodarone in field treatment of primary atrial tachydysrhythmias.

Thirty-nine patients with paroxysmal atrial fibrillation or supraventricular tachycardia randomly received amiodarone or propafenone intravenously at home. Fifteen patients received amiodarone and 24 received propafenone; 87.5% of the patients who received propafenone and 40% of the patients who received amiodarone were converted at home to sinus rhythm (P less than .005). The median time of conversion was 10 minutes (range 5 to 35) for propafenone and 60 minutes (range 20 to 130) for amiodarone (P less than 0.005). When either drug failed to terminate atrial tachydysrhythmias at home, the same drug always restored sinus rhythm with subsequent oral treatment during hospitalization. No major side effects were observed after the infusion of either drug. The incidence of minor side effects was not significantly different between the two drugs. Both the drugs are efficacious and safe in the acute management of primary supraventricular tachydysrhythmias. Propafenone showed a greater rapidity of action.