J Browning

Left Atrial Remodeling in Hypertrophic Cardiomyopathy and Susceptibility Markers for Atrial Fibrillation Identified by Cardiovascular Magnetic Resonance

In hypertrophic cardiomyopathy (HC), atrial fibrillation (AF) is an important determinant of clinical deterioration due to heart failure or embolic stroke. This study characterizes left atrial (LA) structural and functional parameters to establish markers predictive of AF risk, using cardiovascular magnetic resonance (CMR) imaging. We studied 427 consecutive patients with HC in sinus rhythm with CMR (age 44±18 years), including 41 who developed clinically overt AF after study entry (2.6±2.1 years), 49 patients with AF before CMR, 337 patients with HC but without AF, and 244 normal controls. LA chamber was assessed for absolute and indexed end-diastolic volume (LAEDV), end-systolic volume, and percent ejection fraction (LAEF). In the 41 prospectively studied patients with HC who developed AF during follow-up, LAEDV was significantly greater than in patients without AF (146±48 vs 107±37 ml) or in normal controls (81±24 ml, p<0.001). Percent LAEF was lower in patients developing AF (36±10%) than without AF (46±12%) or controls (55±9%, p<0.001). Multivariate analysis identified LAEF (<38%), LAEDV (≥118 ml), and age (≥40 years) as independently associated with AF occurrence. In conclusion, CMR measures of LA remodeling and dysfunction reliably identified patients with HC at risk for future development of AF. Decrease in LAEF represents a strong novel marker of susceptibility to AF in this disease.

Impact of age on treatment and outcomes in ST-elevation myocardial infarction.

OBJECTIVES We hypothesized that older patients in a regional ST-elevation myocardial infarction (STEMI) transfer program would attain comparable treatment to younger patients. BACKGROUND Older patients have been either excluded or underrepresented in STEMI clinical trials. Observational studies suggest that these patients are less likely to receive adjunctive pharmacologies and reperfusion therapy-thrombolysis or percutaneous coronary intervention (PCI)-and therapy is frequently delayed. METHODS We identified a consecutive series of 2,262 STEMI patients (March 2003-December 2008) who either presented or were transferred to Abbott Northwestern Hospital for PCI (<65 years [n = 1285], 65-74 years [n = 436], 75-84 years [n = 381], and ≥85 years [n = 160]). Main outcome measures included time-to-reperfusion therapy, adjunctive medications received, and all-cause mortality. RESULTS Overall time-to-reperfusion therapy was similar across age strata-94 minutes (<65 years), 101 minutes (65-74 years), 106 minutes (75-84 years), and 103 minutes (≥85 years). No difference in adjunctive antiplatelet or anticoagulant medications was seen at hospital admission, and only slight differences in standard post-myocardial infarction medication use were seen by age at hospital discharge. Age was an independent predictor of in-hospital and yearly mortality up to 5 years (1-year mortality 3.4% [<65 years], 9.2% [65-74 years], 15.2% [75-84 years], and 28.9% [≥85 years]; P < .0001). CONCLUSIONS Older patients receive similar care to younger patients when treated in a regional STEMI transfer program. Although all-cause mortality in the elderly is increased, the absolute rates are lower than previously established. Our data suggest primary PCI (including transfer) can be applied to all appropriate STEMI patients, regardless of age.

ST-Segment Elevation Myocardial Infarction Resulting From Stent Thrombosis: An Enlarging Subgroup of High-Risk Patients

To the Editor: Stent thrombosis (ST) is an infrequent but major complication after percutaneous coronary intervention (PCI) and frequently is associated with ST-segment elevation myocardial infarction (STEMI). As the population of stented patients has grown, the number of patients at risk for STEMI

Stress cardiomyopathy depresses left atrial function compared to acute anterior myocardial infarction: left atrial size and function by cardiac MRI

Introduction Little is known about the left atrium (LA) in acute left ventricular (LV) dysfunction. Left atrial systolic function is reported as normal in Acute Myocardial Infarction (AMI), but its relationship to the degree of LV dysfunction is unknown. Also unclear is whether similar relationships hold in primary LV dysfunction such as Stress Cardiomyopathy (SCM). Cardiac MRI (CMR) is ideally suited to quantitate LA size, shape and function.