Impact of post-procedural peripheral fractional flow reserve after drug-coated balloon angioplasty in femoropopliteal lesions.

PURPOSE: The aim of this study was to determine if postprocedural peripheral fractional flow reserve (pFFR) is associated with patency one year after drug-coated balloon (DCB) angioplasty for femoropopliteal (FP) lesions. MATERIALS AND METHODS: Forty-five consecutive patients having 49 de novo FP lesions were enrolled in this prospective, observational study conducted from April 2022 to Aug 2023. The pFFR was measured under hyperemic conditions after the administration of 30 mg of papaverine. The relationship between pFFR and restenosis 12 months after the procedure was determined using receiver operating characteristic (ROC) curve analysis. RESULTS: The one-year follow-up was completed for 47 lesions (95.9 %). Restenosis was detected in 7 lesions (14.9 %). Postprocedural pFFR was significantly higher in the nonrestenosis group compared with the pFFR in the stenosis group (0.95 ± 0.054 vs. 0.88 ± 0.090, p = 0.010). The optimal pFFR cutoff value for predicting restenosis was 0.92 (sensitivity, 0.824; specificity, 0.600). The area under the curve for pFFR was numerically higher than the area under the curve for minimum lumen area (0.73 vs. 0.64, p = 0.22). Rates of freedom from restenosis at one year were significantly higher in the pFFR >0.92 group compared with the pFFR ≤0.92 group (p = 0.0042). CONCLUSION: Postprocedural pFFR was associated with patency at one year after DCB angioplasty for FP lesions.

Utility and optimal dose of nicorandil for physiological assessment of the femoropopliteal artery.

BACKGROUND: Nicorandil is widely used as a vasodilator for the physiological assessment of coronary arteries because of its usefulness and safety; however, there are no data on its use in peripheral arteries. AIMS: To identify the utility of nicorandil and its appropriate dose for the physiological assessment on the femoropopliteal artery. METHODS: We retrospectively enrolled patients from three institutes in which physiological assessment was carried out with various doses of nicorandil before treatment. Twenty-four femoropopliteal artery stenotic lesions from 22 patients were included. The nicorandil doses used were 2, 4, and 6 mg. Twenty-two lesions were also assessed using 30 mg of papaverine. The pressure gradient (PG) and peripheral fractional flow reserve (pFFR) were calculated based on the mean and systolic pressure levels. We examined the correlation of each parameter with the peak systolic velocity ratio (PSVR) based on the duplex ultrasound images using Spearman's rank correlation coefficient. Systemic blood pressure was assessed for safety. RESULTS: The correlations were higher for mean pressure-based parameters than for systolic pressure-based parameters. As the nicorandil dose increased, the correlations among PG, pFFR, and PSVR also increased (mean pressure-based PG: 2 mg, r = 0.360; 4 mg, r = 0.498; 6 mg, r = 0.694, mean pressure-based pFFR: 2 mg, r = -0.479; 4 mg, r = -0.469; 6 mg, r = -0.641). The blood pressure after the administration of 6 mg of nicorandil was low, and the median systemic mean pressure was 65 mmHg. CONCLUSION: A 4 mg dose of nicorandil is effective and safe for the mean pressure-based physiological assessment of lesions in the femoropopliteal artery.

Correlation between physiological assessment and imaging findings during drug-coated balloon treatment for femoropopliteal diseases.

BACKGROUND: This prospective cross-sectional study evaluated the correlation between physiological assessment (PA) and minimum lumen area (MLA) by intravascular ultrasound (IVUS) during drug-coated balloon (DCB) treatment for femoropopliteal (FP) diseases. METHODS: A total of 51 limbs of 44 patients undergoing endovascular treatment with DCB for de novo FP disease were examined from April 2022 to February 2023. PA was conducted at baseline, after balloon dilatation, and after DCB treatment. PA was measured before (pressure ratio; PR) and after vasodilation (peripheral flow fractional flow reserve; pFFR) with the administration of 30 mg papaverine through a guiding catheter. The correlation of PA with percent diameter stenosis (%DS) and MLA was examined, and factors correlated with higher pFFR after balloon dilatation were evaluated in a multivariate analysis. RESULTS: At baseline, there were correlations between pressure ratio (PR) and %DS (coefficients: 0.641 [p < 0.001]) and between pFFR and %DS (0.666 [p < 0.001]). After balloon dilatation, there was no correlation between PR and %DS (coefficients: 0.33 [p = 0.27]) or between pFFR and %DS (0.41 [p = 0.71]). At baseline, PR and MLA were correlated (coefficients: 0.757 [p < 0.001]) as were pFFR and MLA (0.762 [p < 0.001]). After balloon dilatation, PR and MLA were correlated (coefficients: 0.524 [p < 0.001]) as were pFFR and MLA (0.601 [p < 0.001]). Balloon/EEM ratio, calcification >270°, and chronic total occlusion were associated with pFFR after balloon dilatation. CONCLUSION: After balloon dilatation, PA was correlated with MLA by IVUS but not with %DS based on angiography.

Acute and mid-term results of percutaneous coronary intervention for severely calcified coronary artery lesions with orbital atherectomy system.

OBJECTIVES: Severely calcified lesions present many challenges for percutaneous coronary intervention (PCI). This study aimed to assess the safety and efficacy of the orbital atherectomy system (OAS) in treating calcified coronary lesions. METHODS: The present study included 422 consecutive cases (546 lesions) who underwent PCI with OAS in Kyoto Katsura Hospital from February 2018 to December 2021. We assessed the following clinical outcomes after OAS was used for severely calcified lesions: procedure success, angiographic complications, in-hospital Major Adverse Cardiovascular Events (MACE), and mid-term results. The primary endpoint was the combination of incidence of MACE at 12 months, cardiac death, myocardial infarction (MI), and target lesion revascularization (TLR). RESULTS: Of all the cases, 74% patients were men and the mean age was 76.5 years. In total, 81% of lesions were treated with drug-coated balloon, and 14% were implanted with stents. Procedural success rate was 96.3%. Coronary perforation occurred in 0.5% and persistent slow flow in 2% lesions. There was 1 cardiac death (0.5%), 43 periprocedural MIs (10.2%), and no TLR as in-hospital MACE. The incidence of MACE at 12 months was 8.4%, including 2.1% cardiac death and 6.9% TLR. In multivariate analysis, CKD, hemodialysis, and restenosis lesions were independently associated with MACE at 12 months. Periprocedural MI was not an independent predictor of MACE. CONCLUSIONS: This study suggested that OAS is a safe and effective treatment option for calcified coronary lesions with acceptable acute and mid-term results; thus, it can be an alternate for reducing calcified plaque.

A case of picking calcified plaque in the common femoral artery with a long needle: the "calc-pick technique".

An 88-year-old man had intermittent claudication of his right leg. Angiography revealed severely calcified plaque in the common femoral artery. Endovascular treatment was performed by contralateral approach. We attempted to penetrate the center of the calcified plaque and perform balloon dilatation. However, a 0.014-inch stiff guidewire could not enter the center of the lesion. Thus, we used an inner cylinder of 15-cm 20G long needle directly through the retrograde femoral sheath and successfully introduced the guidewire into the calcified plaque. Crosser and balloon dilatation resulted in 50 % stenosis. To cross the center of calcified plaque, it is important to obtain sufficient lumen gain at the non-stenting zone.

Comparison of drug-eluting stents vs. drug-coated balloon after rotational atherectomy for severely calcified lesions of nonsmall vessels.

Calcified lesion is a risk factor for adverse events, even in the drug-eluting stent (DES) era. Recently, drug-coated balloon (DCB) has been shown to have favourable results for in-stent restenosis and small vessels, but its results for calcified lesions are unknown. This study aimed to clarify the rotational atherectomy (RA) and DCB results for calcified lesions of nonsmall vessels. A total of 194 consecutive de novo lesions from 165 cases underwent RA for calcified lesions of nonsmall vessels between January 2016 and August 2018 in a single centre. Overall, 8 cases/10 lesions were excluded because of RA followed plain old balloon angioplasty (POBA). Remaining lesions were grouped into the DES (88 cases/104 lesions) and DCB (69 cases/80 lesions) groups and then compared retrospectively. The primary endpoint was post-discharge major adverse cardiovascular events (MACE) at 1 year, and it was defined as cardiac death, noncardiac death, target-vessel-related myocardial infarction, target lesion revascularization (TLR), and major bleeding (BARC ≥ type 3). There was no difference in the clinical follow-up rate between RA + DES (96/104 lesions) and RA + DCB (78/80 lesions). The post-discharge MACE values after 1 year of RA + DES and RA + DCB were 8% and 11% (P = 0.30), respectively, in terms of cardiac death (0% vs. 0%, respectively), noncardiac death (4% vs. 3%, respectively, P = 0.36), target-vessel-related myocardial infarction (0% vs. 0%, respectively), TLR (4% vs. 8%, respectively, P = 0.30), and major bleeding (1% vs. 0%, respectively). For calcified lesions of nonsmall vessels, RA + DCB showed good results as well as RA + DES. RA + DCB is a potential new strategy for these lesions.

Questionnaire in patients with aborted sudden cardiac death due to coronary spasm in Japan.

OBJECTIVES: We investigated the medical or mechanical therapy, and the present knowledge of Japanese cardiologists about aborted sudden cardiac death (ASCD) due to coronary spasm. METHODS: A questionnaire was developed regarding the number of cases of ASCD, implantable cardioverter-defibrillator (ICD), and medical therapy in ASCD patients due to coronary spasm. The questionnaire was sent to the Japanese general institutions at random in 204 cardiology hospitals. RESULTS: The completed surveys were returned from 34 hospitals, giving a response rate of 16.7%. All SCD during the 5 years was observed in 5726 patients. SCD possibly due to coronary spasm was found in 808 patients (14.0%) and ASCD due to coronary spasm was observed in 169 patients (20.9%). In 169 patients with ASCD due to coronary spasm, one or two coronary vasodilators was administered in two-thirds of patients [113 patients (66.9%)], while more than 3 coronary vasodilators were found in 56 patients (33.1%). ICD was implanted in 117 patients with ASCD due to coronary spasm among these periods including 35 cases with subcutaneous ICD. Majority of cause of ASCD was ventricular fibrillation, whereas pulseless electrical activity was observed in 18 patients and complete atrioventricular block was recognized in 7 patients. Mean coronary vasodilator number in ASCD patients with ICD was significantly lower than that in those without ICD (2.1 ± 0.9 vs. 2.6 ± 1.0, p < 0.001). Although 16 institutions thought that the spasm provocation tests under the medications had some clinical usefulness of suppressing the next fatal arrhythmias, spasm provocation tests under the medication were performed in just 4 institutions. CONCLUSIONS: In the real world, there was no fundamental strategy for patients with ASCD due to coronary spasm. Each institution has each strategy for these patients. Cardiologists should have the same strategy and the same knowledge about ASCD patients due to coronary spasm in the future.

Effect of pioglitazone on cardiometabolic profiles and safety in patients with type 2 diabetes undergoing percutaneous coronary artery intervention: a prospective, multicenter, randomized trial.

Pioglitazone has superior antiatherosclerotic effects compared with other classes of antidiabetic agents, and there is substantial evidence that pioglitazone improves cardiovascular (CV) outcomes. However, there is also a potential risk of worsening heart failure (HF). Therefore, it is clinically important to determine whether pioglitazone is safe in patients with type 2 diabetes mellitus (T2DM) who require treatment for secondary prevention of CV disease, since they have an intrinsically higher risk of HF. This prospective, multicenter, open-label, randomized study investigated the effects of pioglitazone on cardiometabolic profiles and CV safety in T2DM patients undergoing elective percutaneous coronary intervention (PCI) using bare-metal stents or first-generation drug-eluting stents. A total of 94 eligible patients were randomly assigned to either a pioglitazone or conventional (control) group, and pioglitazone was started the day before PCI. Cardiometabolic profiles were evaluated before PCI and at primary follow-up coronary angiography (5-8 months). Pioglitazone treatment reduced HbA1c levels to a similar degree as conventional treatment (pioglitazone group 6.5 to 6.0%, P < 0.01; control group 6.5 to 5.9%, P < 0.001), without body weight gain. Levels of high-molecular weight adiponectin increased more in the pioglitazone group than the control group (P < 0.001), and the changes were irrespective of baseline glycemic control. Furthermore, pioglitazone significantly reduced plasma levels of natriuretic peptides and preserved cardiac systolic and diastolic function (assessed by echocardiography) without incident hospitalization for worsening HF. The incidence of clinical adverse events was also comparable between the groups. These results indicate that pioglitazone treatment before and after elective PCI may be tolerable and clinically safe and may improve cardiometabolic profiles in T2DM patients.

Short-Term Subcutaneous Fondaparinux and Oral Edoxaban for Acute Venous Thromboembolism.

BACKGROUND: No studies have compared treatment efficacy between subcutaneous (SC) fondaparinux and oral edoxaban, which are categorized as factor Xa inhibitors, for venous thromboembolism (VTE) in the acute phase, and only a limited number of imaging-based quantitative studies have evaluated treatment.Methods and Results:In this open-label, randomized study, 50 patients with acute non-massive pulmonary embolism (PE) and/or deep-vein thrombosis (DVT) were assigned to fondaparinux or edoxaban groups. Lower-limb venous ultrasonography (US), and chest computed tomography (CT) were compared before and 7 days after treatment. Thrombus volume in DVT was calculated using quantitative ultrasound thrombosis (QUT) score on US. For evaluation of PE thrombus volume, lung perfused blood volume (PBV) on CT was calculated. The measurements before and after treatment, respectively, were as follows: QUT score: fondaparinux, 8.1±7.3 to 4.1±4.5; edoxaban, 7.7±6.3 to 4.4±4.3, both significant decreases (P=0.001, P<0.001, respectively); lung PBV: fondaparinux, 32.0±7.8 to 32.1±8.2 HU; edoxaban, 34.2±8.6 to 38.5±11.8 HU (P=0.732, P=0.426, respectively). On subjective CT-based evaluation, all pulmonary artery-related filling defects decreased/disappeared after treatment in both groups (P=NS). CONCLUSIONS: Both SC fondaparinux and oral edoxaban are effective in acute VTE. Effects on thrombus regression on imaging-based quantitative measurement did not differ between the 2 drugs.

Clinical usefulness of the Driver(®) stent in a retrospective, collaborative, multicenter, open-label study in Japanese real-world patients with coronary artery disease and the drug-eluting stent era.

The objectives of the present study were to determine predictors for target lesion revascularization (TLR) and to examine the clinical usefulness of the Driver(®) stent (a cobalt alloy, modular-type) in Japanese patients with coronary artery disease. Data on 631 Japanese patients including 241 with stable angina and 361 with acute coronary syndrome-who had been implanted with the Driver(®) stent (805 lesions) between August 2004 and February 2005-were collected retrospectively; 95.0 and 81.7% of these lesions were de novo and ACC/AHA classification B2/C type, respectively. Early angiography of 622 patients revealed 1) the preprocedural minimal lumen diameter (MLD) of 0.80 ± 0.51 mm, with lesion lengths of 17.1 ± 7.3 mm, and 2) the postprocedural MLD of 2.95 ± 0.55 mm, with MLD gains of 2.14 ± 0.68 mm. At 270 days of clinical follow-up, the incidences of major adverse cardiac events (MACE), TLR, and early stent thrombosis (ST) were 18.8, 14.7, and 0.2%, respectively; the TLR rate decreased statistically significantly to 5.3 and 5.9% when implanting the Driver(®) stent (3.5 and 4.0 mm) and by IVUS, respectively. Absence rate of diabetes mellitus, presence rate of AMI, presence rate of stent diameters of ≥3.5 mm, and presence rate of IVUS-guided PCI showed lower TLR rates, with statistically significant differences. Uni- and multivariate analyses revealed that AMI and stent diameter (≥3.5 mm) are significant predictors for TLR (0.048 and 0.047, respectively), indicating that physicians are recommended to consider these variables when selecting candidate real-world patients for IVUS-guided PCI.

Very late bare metal stent thrombosis presenting with acute myocardial infarction: 14 years after coronary stenting.

Fourteen years previously, a 67-year-old man underwent percutaneous coronary intervention (PCI) for proximal left anterior descending artery lesion with a bare metal stent (BMS) for acute myocardial infarction (AMI) and attained an excellent result. Ticlopidine (200 mg) was administered for one month and 100 mg of aspirin was daily has been continued. One year after PCI, coronary angiography showed no restenosis. However, 14 years after PCI, he suffered from AMI due to stent thrombosis. Intracoronary aspiration thrombectomy and implantation of a drug-eluting stent were successful. This report demonstrates evidence of a very late case of stent thrombosis with the use of BMS.

Predischarge angiographical evaluation of radial artery graft harvested by endoscopic harvesting system.

OBJECTIVE: Endoscopic radial artery harvesting (ERAH) has superior cosmetic advantages over conventional harvesting methods. With instrumental advancements, these techniques have become easier to adopt and require less time to learn. In most reported cases, the quality of harvested conduits is discussed based on macroscopic and histologic examinations and clinical outcomes. However, predischarge angiography gives a straightforward answer regarding quality of harvested conduit. The aim of this study is to assess the quality of endoscopically harvested radial artery by predischarge angiographic evaluation. METHODS: Endoscopic procedure using VasoView 4 system was performed in 87 patients between September 2004 and December 2007, and 78 predischarge angiographical evaluations were completed and reviewed. Mean age of the patients was 66 ± 10 years and 18% were women. After ERAH was performed, accompanying veins were dissected by ultrasound scalpel. All conduits were as aortocoronary bypass under cardiopulmonary bypass. RESULTS: Mean arm ischemic time was 32 ± 13 minutes and length of harvested conduit was 17.8 ± 1.3 cm. Predischarge angiography demonstrated two occlusions at the proximal anastomosis in the 51st and 71st cases, although intraoperative flow study showed normal flow patterns in both cases. Stenosis in the conduits was observed in the first, sixth, and seventh cases. No further angiographical problems were found in the remaining conduits. CONCLUSIONS: Based on the angiographical results, problems with the harvested conduits occurred only in initial period. ERAH with VasoView system provides satisfactory angiographical quality after initial learning curve.

Balloon rupture during coronary angioplasty causing dissection and intramural hematoma of the coronary artery; a case report.

A 73-year-old male with diabetes mellitus was referred for coronary angiography (CAG). He presented with stable effort angina pectoris. CAG showed a significant stenotic lesion in the proximal-segment of the left anterior descending (LAD) coronary artery with heavy calcification. He then underwent angioplasty for the LAD stenosis. On the second balloon dilatation, the balloon was inflated to 22 atm, at which point the balloon waist had not yet yielded and balloon rupture occurred. Immediately after the procedure, CAG showed no-reflow phenomena and chest pain occurred. Intravascular ultrasound (IVUS) imaging revealed a dissection into the media with extension into the medial space without reentry, and demonstrated significant stenosis and obstruction of the distal LAD with a semilunar echo-dense intramural hematoma. To bail out, two bare metal stents were deployed. After the procedure, proper stents expansion and no residual dissection flap were detected either by IVUS or CAG. The final CAG showed a good result with TIMI-3 coronary flow. This case highlights balloon rupture during coronary angioplasty with heavy calcification caused no-reflow phenomena by dissection and intramural hematoma of the coronary artery. We could bail out hematoma by coronary stent implantation with complete cover of the coronary dissection.

The etiology of 'smoker's paradox' in acute myocardial infarction with special emphasis on the association with inflammation.

Despite increased risk for coronary artery disease and acute myocardial infarction (AMI), prior studies have found that smokers with AMI have lower mortality rates than nonsmokers, a phenomenon often termed 'smoker's paradox'. The present study was designed to examine the etiology of 'smoker's paradox', especially with respect to the association with inflammation. The subjects included 528 consecutive AMI patients who were admitted within 24 hours of onset and underwent successful coronary intervention. Of the 528 subjects, 232 (44%) were smokers. The cardiac mortality rates over a 6 month period was significantly lower in the smoking group than the nonsmoking group (3% versus 9%, P = 0.01). There were significantly more male patients in the smoking group, and the smoking group was significantly younger than the nonsmoking group (P < 0.0001). The value of high sensitivity C-reactive protein (hs-CRP) on admission and 24 hours after onset, and serum amyloid A protein (SAA) were significantly higher, and acute phase BNP was significantly lower (hs-CRP on admission 1.36 +/- 1.03 mg/dL versus 0.75 +/- 0.82 mg/dL, P = 0.02, hs-CRP at 24 hours 3.86 +/- 4.32 mg/dL versus 2.90 +/- 3.46 mg/dL, P = 0.008, SAA; 288 +/- 392 microg/dL versus 176 +/- 206 microg/dL, P < 0.05, BNP; 248 +/- 342 pg/mL versus 444 +/- 496 pg/mL, P = 0.0002) in the smoking group than in the nonsmoking group. The early ST-segment resolution rate was higher in the smoking group compared with the nonsmoking group (80% versus 66%, P = 0.003). The reason why smokers with AMI have lower mortality rates than nonsmokers, the so-called 'smoker's paradox', is believed to be because smoking induces inflammation and smokers may have less damage to microvascular function after primary percutaneous coronary intervention.

A case report of very late thrombosis of coronary bare-metal stent 10 years after stenting.

Although late stent thrombosis is not uncommon with the use of drug-eluting stents, it is unusual with the use of bare-metal stents (BMS) because stent endothelialization is considered to be completed 4 weeks after the intervention.(1) A 64 year-old male had undergone percutaneous coronary intervention (PCI) for a proximal left anterior descending (LAD) artery lesion with a BMS and excellent angiographic results were obtained. Two hundred mg of ticlopidine was prescribed for one month and 100 mg of aspirin daily was continued. One year after stent implantation, coronary angiography (CAG) showed no restenosis. Ten years and 7 months after stent implantation, he suffered an acute myocardial infarction due to stent thrombosis. Intra-coronary aspiration thrombectomy was successful. To the best of our knowledge, the longest delayed case of BMS thrombosis is 5 years after stent implantation.(2) Our report demonstrated evidence of the latest reported case of stent thrombosis with the use of a BMS.

Two cases of very late stent thrombosis after implantation of a sirolimus-eluting stent presenting as AMI.

Stent thrombosis after sirolimus-eluting stent (SES) implantation has been reported to occur at 6 hours to 26 months after the procedure and usually within 2 weeks after discontinuation of antiplatelet medication. However, there are very few reports of stent thrombosis after 2 years. We report 2 cases of very late stent thrombosis after implantation of a sirolimus-eluting stent presenting as acute myocardial infarction (AMI). These late thromboses occurred about 2 years after SES implantation and over 1.5 years after discontinuation of ticlopidine.

The relationship between acute phase serum amyloid A (SAA) protein concentrations and left ventricular systolic function in acute myocardial infarction patients treated with primary coronary angioplasty.

BACKGROUND: Our study was planned to investigate the relationship between plasma levels of serum amyloid A protein (SAA) concentrations and the subsequent left ventricular systolic function in patients with acute myocardial infarction (AMI) treated with primary coronary angioplasty. METHODS AND RESULTS: Reperfusion by primary percutaneous coronary intervention was successful in 486 consecutive AMI patients who were admitted within 12 hours of onset. Plasma SAA concentrations were evaluated 24 hours after onset. Left ventricular (LV) function was serially determined by left ventriculography performed in the acute (soon after recanalization) and chronic phases (6 months after onset). (I) There was no significant correlation between SAA concentration and acute phase left ventricular ejection fraction (LVEF) or regional wall motion (RWM). (II) The SAA concentration was significantly correlated with both highly sensitive C-reactive protein (hs-CRP) and the peak-CK value (hs-CRP: r = 0.69, P < 0.0001, peak-CK: r = 0.21, P = 0.0003). (III) SAA was significantly negatively correlated with both LVEF and RWM in the chronic phase (LVEF: r = -0.42, P = 0.001; RWM: r = -0.41, P = 0.007). (IV) The plasma level of SAA also showed a significant negative correlation with the differences in LVEF between the 2 stages (delta-LVEF) (r = -0.43, P = 0.02). CONCLUSION: In the setting of AMI, plasma SAA concentrations may be closely related to subsequent left-ventricular systolic dysfunction.

["Smoker's paradox" in patients with acute myocardial infarction receiving primary coronary intervention].

OBJECTIVES: Smokers with acute myocardial infarction have lower mortality rates than non-smokers despite increased risk for coronary artery disease. This study assessed the effects of smoking on complications and outcomes after acute myocardial infarction, and investigated the relationship between the clinical factors and the paradoxical effects of smoking in patients receiving primary coronary intervention. METHODS: Subjects were 367 consecutive patients with acute myocardial infarction who were admitted within 24 hr of onset and underwent successful coronary intervention, 165 (45%) of whom were smokers. RESULTS: The smoking group contained significantly more male patients, and the smoking group was significantly younger than the non-smoking group (p < 0.0001). The value of acute phase brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) were significantly lower (BNP: 250 +/- 366 vs 448 +/- 513pg/ml, p = 0.0002; ANP: 48 +/- 77 vs 74 +/- 82pg/ml, p = 0.005) in the smoking group. Peak creatine kinase time from onset was significantly earlier (12.9 +/- 9.3 vs 16.1 +/- 10.0 hr, p = 0.049) in the smoking group. Left ventricular ejection fraction in the chronic phase was significantly better in the smoking group (58 +/- 13% vs 52 +/- 14%, p = 0.03). The early ST-segment resolution rate was higher in the smoking group (81% vs 67%, p = 0.003), and there were significantly fewer patients with heart failure in the smoking group than in the non-smoking group (28% vs 41%, p = 0.01). The cardiac mortality rate during 6 months was significantly lower in the smoking group (3% vs 9%, p = 0.01). The beneficial effects of smoking on the prognosis were related with the differences in sex and age of the study group. CONCLUSIONS: The reason why smokers with acute myocardial infarction have lower mortality rates than non-smokers, the "smoker's paradox", may be related to less damage to the microvascular function after primary coronary intervention, with lower BNP and better left ventricular ejection fraction.