Citations

Background— Little is known about the clinical value of stress imaging studies in asymptomatic patients after percutaneous coronary intervention (PCI). Methods and Results— Residents of Olmsted County, MN, who underwent PCI were followed up for the occurrence of stress imaging (stress nuclear or stress echocardiography), coronary angiography, or coronary artery bypass grafting (without angiography) as initial procedures after PCI. Patients whose first follow-up procedure was a stress imaging test were evaluated for their symptom status at the time of the study and whether they underwent angiography or revascularization (PCI or coronary artery bypass grafting) within 90 days. Of 1848 patients who underwent PCI during the study period, 710 (38%) had stress imaging as their initial procedure after PCI, and 241 (13% of the entire cohort) were asymptomatic at the time of testing. The majority (86%) of these 241 patients underwent PCI for acute myocardial infarction or unstable angina. Within 90 days of stress imaging, 16 of the 241 asymptomatic patients underwent angiography, and 2 patients were revascularized. Stratified by timing after PCI, none of 138 asymptomatic patients tested within 2 years of PCI underwent revascularization. Two of 103 asymptomatic patients tested after 2 years from PCI underwent revascularization. Compared with patients who were asymptomatic at the time of stress imaging, patients who did not undergo any follow-up procedures (stress imaging, angiography, or coronary artery bypass grafting) after the index PCI were older, were more likely to have comorbidities, and had significantly greater all-cause mortality ( P <0.001). Conclusions— In a population-based sample of patients undergoing PCI primarily for acute coronary syndromes, 1 in 8 had subsequent stress imaging when they were asymptomatic. These stress imaging tests resulted in further revascularization in <1% of patients. The low rate of downstream revascularization suggests that stress imaging in asymptomatic patients after PCI has low value.

Introduction Pulmonary vein isolation is an effective therapy for curing symptomatic atrial fibrillation (AF). While it is known the severity of left atrial (LA) enlargement affect the success of AF ablation, little is known the impact of intracardiac pressure on the ablation outcome. Methods This prospective study consisted of 63 patients (mean age 57±9 years, 73% male) who underwent catheter-based pulmonary vein isolation for drug refractor symptomatic AF (48% paroxysmal, 52% persistent). All patients underwent simultaneous echocardiography and haemodynamic measurements including left ventricular end systolic pressure (LVEDP), mean left atrial pressure (LAP) and dP/dtmax using Millar catheter at the time of procedure during AF. Left atrial volume (LAV) was measure by biplane area length method. Recurrence of AF was defined as episodes of AF more than 5 min documented in 24h ambulatory ECG or event monitor. Results After a mean follow-up duration of 16±7 months, AF elimination off anti-arrhythmic drugs was achieved in 70 % (44/63) of patients. Among the echographic and haemodynamic measurements, the baseline LAV and mean LAP were 57.62±25.39 ml and 12.19±4.57 mm Hg in AF free patients compared to 81.20±40.88 ml (p=0.02) and 16.46±4.14 mm Hg (p=0.01) in AF recurrence groups. Univariate and multivariate analysis showed LAP was the only independent predictor of the recurrence with an adjusted odd ratio of 1.27 (95% CI 1.04 to 1.54, p=0.03, table). Conclusion LAP is a determinant of AF recurrence after AF ablation. Therapies towards reduction of LA filling pressure, especially in patients with elevated LAP, may improve the outcome of ablation. Table Baseline clinical characters in the recurrence group and non-recurrence group Non-recurrence (N=44) recurrence (N=19) Univariate Multivariate P 95% CI P 95% CI Age (ys) 57.39±9.92 59.26±10.47 0.49 0.97, 1.08 – – AF type, persistent AF no. (%) 23 (53%) 10 (50%) 0.97 0.34, 2.98 – – AF duration (ys) 5.84±5.43 8.08±7.66 0.20 0.99, 1.05 – – LA volume (mL) 57.62±25.39 81.20±40.88 0.02 1.01, 1.05 0.30 0.99, 1.05 LVEDP (mm Hg) 10.25±14.54 11.25±5.75 0.81 0.96, 1.06 – – dP/dt max (mm Hg/s) 1294.02±337.13 1211.77±225.36 0.47 0.99, 1.02 – – Mean LAPmean (mm Hg) 12.19±4.57 16.46±4.14 0.01 1.06, 1.50 0.02 1.04, 1.54 Pulmonary vein isolation is an effective therapy for curing symptomatic atrial fibrillation (AF) but the success rate ranged wide. This study aimed to investigate the effect of LAP on AF recurrence.

Background— A patent foramen ovale (PFO) may permit arterial embolization of thrombi that accumulate on the leads of cardiac implantable electronic devices in the right-sided cardiac chambers. We sought to determine whether a PFO increases the risk of stroke/transient ischemic attack (TIA) in patients with endocardial leads. Methods and Results— We retrospectively evaluated all patients who had endocardial leads implanted between January 1, 2000, and October 25, 2010, at Mayo Clinic Rochester. Echocardiography was used to establish definite PFO and non-PFO cohorts. The primary end point of stroke/TIA consistent with a cardioembolic etiology and the secondary end point of mortality during postimplantation follow-up were compared in PFO versus non-PFO patients with the use of Cox proportional hazards models. We analyzed 6075 patients (364 with PFO) followed for a mean 4.7±3.1 years. The primary end point of stroke/TIA was met in 30/364 (8.2%) PFO versus 117/5711 (2.0%) non-PFO patients (hazard ratio, 3.49; 95% confidence interval, 2.33–5.25; P <0.0001). The association of PFO with stroke/TIA remained significant after multivariable adjustment for age, sex, history of stroke/TIA, atrial fibrillation, and baseline aspirin/warfarin use (hazard ratio, 3.30; 95% confidence interval, 2.19–4.96; P <0.0001). There was no significant difference in all-cause mortality between PFO and non-PFO patients (hazard ratio, 0.91; 95% confidence interval, 0.77–1.07; P =0.25). Conclusions— In patients with endocardial leads, the presence of a PFO on routine echocardiography is associated with a substantially increased risk of embolic stroke/TIA. This finding suggests a role of screening for PFOs in patients who require cardiac implantable electronic devices; if a PFO is detected, PFO closure, anticoagulation, or nonvascular lead placement may be considered.

BackgroundRecent studies have shown that magnetic resonance imaging (MRI) of patients with pacemakers can be safely performed under careful monitoring, but they excluded patients with recently implanted devices. Patients with recent implants may be at a greater risk for complications during MRI imaging due to lack of lead and wound maturity.MethodsWe implemented a clinical protocol for MRI imaging of patients with implanted cardiac devices, and prospectively collected data. For this study, we retrospectively analyzed two groups of patients: those with recently implanted (≤42 days) and nonrecently implanted (>42 days) leads at the time of MRI scanning. All devices were interrogated before and after scanning, and were reprogrammed during the scan as per protocol.ResultsOf the 219 scans (in 171 patients), eight included patients with recently implanted (range: 7–36 days) and 211 with only nonrecently implanted pacemaker leads. During the scan, there were no complications in the early or late group. In one patient imaged 79 days postimplant, frequent premature ventricular complexes were noted during the scan, requiring no action. No patient reported pain during or immediately after the procedure. No clinically significant changes in function were seen at subsequent follow up (average 104 days post‐MRI). Compared to patients with nonrecently implanted leads, there was no difference in any parameter between the two groups.ConclusionsWith a strong clinical indication and with careful monitoring, MRI imaging is feasible in patients with recently implanted pacemakers, although experience is limited.

BackgroundPatients with preexisting mild cognitive impairment or dementia may be at increased risk for developing cardiac device complications due to an impaired ability to follow postimplant care instructions. We sought to determine whether rates of infection, lead dislodgement, or appropriate or inappropriate implantable cardioverter defibrillator (ICD) shocks are increased in this population.MethodsMedical charts of 561 patients with mild cognitive impairment or dementia who underwent pacemaker (PM) or ICD implantation between January 2002 and October 2009 at Mayo Clinic were identified. A total of 134 patients who were diagnosed with cognitive impairment or dementia before device implantation or within 1 year of implantation were compared with 134 matched controls. Information was collected on patient characteristics, comorbid medical conditions, ejection fraction, complications, device type, device therapy, and mortality. Device information was prospectively entered into a database and retrospectively reviewed.ResultsOf the 134 patients with mild cognitive impairment and dementia, 99 underwent PM implantation and 35 underwent ICD implantation. Compared to controls, there was no difference in patient characteristics, ejection fraction, or comorbidities except for diabetes, which was more prevalent in the cognitively impaired and demented group (18.7% vs 30.6%, P = 0.02). There was no difference in device therapy and complications (14.4% vs 5.8%, P = 0.268). However, there was a decreased survival in patients with cognitive impairment and dementia when compared to the control group (42% vs 67% at 5 years, P = 0.007).ConclusionPatients with cognitive impairment and standard device indications are not at increased risk for device complications and therapy but their survival is much lower than in matched controls. The cause of this lower survival is unknown but may be related to the underlying neurological disease. Presence of cognitive impairment should therefore be considered when contemplating implantation of a cardiac device.

BackgroundOctogenarians (>80 years) have been underrepresented in clinical trials of cardiac resynchronization therapy (CRT).ObjectiveTo determine the benefit of CRT with or without a defibrillator in older elderly patients.MethodsWe retrospectively studied consecutive patients who received CRT at our institution from 2002 through 2008. New York Heart Association (NYHA) class and echocardiographic parameters were assessed before and after CRT. Thirty‐day complications after device implant were collected. Survival data were obtained from the national death and location database. Data were compared between those 80 years and younger and those older than 80 years.ResultsOf 728 patients identified, 90 (12.4%) were older than 80 years. After CRT, older and younger patients had similar improvements in NHYA class (P = 0.41), ejection fraction (P = 0.48), and mitral valve regurgitation (MR) severity (P = 0.42). In the older patients, defibrillator implantation was associated with comparable improvement in NYHA class, ejection fraction, and MR grade severity (P > 0.05), as in those without a defibrillator. Overall survival was worse in octogenarians than in the younger patients by Kaplan‐Meier estimates (P = 0.001). Multivariate analysis showed similar survival between the younger and older subjects (hazard ratio, 1.23; 95% confidence interval, 0.83–1.84; P = 0.31). The observed complication rate in all study subjects was 12.2%, with no difference between the two age groups.ConclusionOctogenarian patients who received CRT with or without a defibrillator for advanced heart failure had similar clinical benefits as younger patients. CRT should not be withheld from octogenarians meeting current selection guidelines.

Background —Quantitative measures of myocardial perfusion defect severity from acute 99m Tc-sestamibi tomographic images (nadir) have correlated closely with collateral and residual antegrade blood flow during acute myocardial infarction. The purpose of this study was to determine whether a viability threshold could be identified from this measure in patients with acute myocardial infarction treated in a homogeneous manner with successful reperfusion therapy. Methods and Results —The study group consisted of 61 patients with acute myocardial infarction with a risk area of >6% LV treated with primary angioplasty between 120 and 240 minutes after symptom onset. All patients were injected with 20 to 30 mCi of 99m Tc-sestamibi before primary angioplasty and imaged after the procedure. Acute myocardium at risk (MAR) and subsequent infarct size (IS) were quantified by a threshold program. Severity (nadir) from the acute image was the lowest ratio of minimal/maximum counts from 5 short-axis slices. Infarct location was anterior in 22 and inferior in 39 patients. MAR was 33±15% LV and IS was 13±15% LV: 23 patients had no infarction despite MAR similar to those with infarction. Receiver-operator characteristic curve analysis identified a nadir value of 0.26 as providing the best separation of patients with and without infarction (sensitivity, 74%; specificity, 74%). This nadir threshold varied by infarct location: anterior defect, 0.21; inferior defect, 0.31. The sensitivity and specificity for absent infarction for these values were anterior, 69% and 67%, and inferior, 88% and 84%, respectively. Conclusions —In a time frame in which the presence of residual blood flow is important, the severity of the acute 99m Tc-sestamibi defect can be used to predict whether infarction will develop despite successful reperfusion.

Background —The appropriate management of patients with intermediate-risk Duke treadmill scores is not established. The purpose of this study was to determine the long-term risk of subsequent cardiovascular events in patients with an intermediate-risk treadmill score who do not have myocardial perfusion defects on radionuclide imaging. Methods and Results —The existing databases of the nuclear cardiology laboratories of 4 academic institutions were searched retrospectively. A total of 4649 patients were identified who had intermediate-risk Duke treadmill scores (−10 to 4), normal or near-normal exercise single photon-emission computed tomographic myocardial perfusion images using either thallium-201 or technetium-99m sestamibi, and no previous coronary revascularization. Follow-up was 95% complete. Cardiovascular survival was 99.8% at 1 year, 99.0% at 5 years, and 98.5% at 7 years. Cardiac survival free of myocardial infarction was similarly high at 96.6% at 7 years. Cardiac survival free of myocardial infarction or revascularization was 87.1% at 7 years. Near-normal scans and cardiac enlargement were independent predictors of time to cardiac death. Seven-year cardiac survival was still high at 97.0% in the 357 patients with near-normal scans and normal cardiac size and somewhat lower, at 89.0%, in the 167 patients with cardiac enlargement. Conclusions —Patients with an intermediate-risk treadmill score but with normal or near-normal exercise myocardial perfusion images and normal cardiac sizes are at low risk for subsequent cardiac death and can be safely managed medically until their symptoms warrant revascularization. The appropriate management of patients with cardiac enlargement will remain a matter of clinical judgment.

Background —The prognostic value of tomographic myocardial perfusion imaging with dipyridamole or adenosine in patients with left bundle-branch block has not been established. Methods and Results —The study group consisted of 245 patients with left bundle-branch block who underwent tomographic (single photon emission tomography) myocardial perfusion imaging with thallium-201 (n=173) or technetium-99m sestamibi (n=72) and either dipyridamole (n=153) or adenosine (n=92) stress. Patients were prospectively classified into two groups. Patients were classified as “high risk” if they had (1) a large severe fixed defect (n=28), (2) a large reversible defect (n=36), or (3) cardiac enlargement and either increased pulmonary uptake (thallium) or a decreased resting ejection fraction (sestamibi) (n=20). The remaining 161 patients (66% of the study group) were at “low risk.” Follow-up was 99% complete at 3±1.4 years. Three-year overall survival was 57% in the high-risk group compared with 87% in the low-risk group ( P <.0001). Survival free of cardiac death/nonfatal myocardial infarction/cardiac transplantation was 55% in the high-risk group and 93% in the low-risk group ( P <.0001). The presence of a high-risk scan had significant incremental prognostic value after adjustment for age, sex, diabetes, and previous myocardial infarction ( P <.0001). Patients with a low-risk scan had an overall survival that was not significantly different from that of a US age-matched population ( P =.86). Conclusions —Tomographic myocardial perfusion imaging with adenosine or dipyridamole stress provides important prognostic information in patients with left bundle-branch block, which is incremental to clinical assessment.