Martin E. Matsumura

Relation of Pre-Event Use of Inhibitors of the Renin-Angiotensin System With Myocardial Infarct Size in Patients Presenting With a First ST-Segment Elevation Myocardial Infarction

Agents that block the renin-angiotensin system (RAS), including angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, are of proven benefit in patients after ST-segment elevation myocardial infarction (STEMI). However, no studies have evaluated the benefit of pre-event use of RAS inhibitors before STEMI. A retrospective review was performed of patients admitted to a single hospital with the diagnosis of STEMI and without a history of coronary disease or the equivalent, including diabetes mellitus, peripheral vascular disease, or stroke. Patients were stratified according to the use of RAS inhibitors before STEMI. Compared to patients not taking RAS inhibitors, patients who were taking RAS inhibitors had a lower peak troponin I level (79 vs 120 ng/dl, p = 0.016). Of the patients who had medically treated hypertension, those receiving RAS inhibitors had a significantly lower peak troponin I compared to those receiving non-RAS agents (79 vs 130 ng/dl, p = 0.015), despite equivalent blood pressure across the 2 groups. The beneficial effect of RAS inhibitor pretreatment remained when concomitant aspirin and statin use were controlled for. In conclusion, in patients presenting with a first STEMI, pretreatment with RAS inhibitors conferred a cardioprotective effect. The mechanism of this benefit appears to be independent of an effect on blood pressure control and was not wholly due to the effect of concomitant use of other medicines known to be protective in patients with STEMI.

The Effect of Beta-Blocker Dosing Strategy on Regulation of Perioperative Heart Rate and Clinical Outcomes in Patients Undergoing Vascular Surgery: A Randomized Comparison

The optimal dosing strategy for perioperative beta-blockers to safely achieve recommended target heart rates (HRs) by current guidelines is not well defined. An HR-titrated perioperative beta-blocker dosing regimen versus a fixed-dose regimen was assessed by clinical outcomes, postoperative heart rate, and beta-blocker-related complications. Patients (n = 64) scheduled to undergo moderate- to high-risk vascular surgery and without contraindications to beta-blockade were randomized to either a fixed-dose or HR-titrated beta-blocker dosing schedule. Clinical outcomes and HRs were followed immediately preoperatively to 24 hr postoperatively. A difference in mean HR between the two dosing arms was significant immediately postoperatively (70.1 vs. 58.2 bpm for fixed dose and HR-titrated arms, respectively; p = 0.012) but at no other time points. However, the HR-titrated strategy led to a significant reduction in the percentage of HR measurements >80 bpm (34.5% vs. 16.1%, p < 0.001) and to a significant reduction in absolute HR change (17.5 vs. 22.5 bpm, p = 0.034). There were no significant differences in the occurrence of asymptomatic hypotension between the two study arms, and no beta-blocker-related adverse events occurred in either study arm. An aggressive, HR-titrated perioperative beta-blocker dosing strategy was associated with more consistent maintenance of postoperative HRs within the range recommended by current guidelines and did not result in increased drug-related adverse events. The question of what is the best perioperative beta-blocker dosing regimen warrants further evaluation in a large-scale clinical trial.

Carotid Intima-Media Thickness Assessment in Refinement of the Framingham Risk Score: Can It Predict ST-Elevation Myocardial Infarction? A Pilot Study

Patients who suffer a first ST‐elevation myocardial infarction (STEMI) typically have fewer identifiable risk factors than those who suffer other types of acute coronary syndromes. As such, risk assessment tools such as the Framingham Risk Score (FRS) often fail to classify these patients as high risk. In this study, we tested the ability of assessment of carotid intima‐media thickness (CIMT) to enhance the ability to identify patients who are at risk for STEMI, using a CIMT‐derived “vascular age” in place of chronologic age in the calculation of FRS. We applied a CIMT‐based vascular age to the assessment of FRS in a cohort of patients who presented with a first STEMI. Using CIMT‐derived vascular age in place of chronologic age increased both the mean FRS and predicted 10 year cardiovascular event rate of the cohort. More importantly, the use of a CIMT‐derived vascular age in the calculation of FRS significantly improved the ability to identify patients with STEMI as high risk and candidates for statin therapy based on ATPIII criteria (19.2% vs. 57.7%, P = 0.010). The use of CIMT to derive a vascular age may improve the ability of FRS to identify patients at risk for STEMI.

Freedom from complications related to dual ball-and-cage mechanical valve prostheses despite thirty years without anticoagulation.

We report a case of a 57-year-old patient with a history of a Starr-Edwards mitral valve prosthesis and DeBakey-Surgitool aortic valve prosthesis implanted 30 years ago who presented with symptoms consistent with class IV heart failure. The patient had been on no anticoagulation for approximately 30 years secondary to recurrent epistaxis occurring two years after starting warfarin therapy postoperatively. Throughout the patients lifetime he experienced no thromboembolic complications from the lack of anticoagulation, despite developing concomitant atrial fibrillation approximately ten years prior to admission. In place of warfarin the patient had substituted large doses of aspirin. A workup revealed normal function of the mechanical valves for this extensive period.

Plutonium 238 Pacemaker Failure Secondary to Lead Fracture

First implanted in France in 1970, the plutonium-powered pulse generator was a solution to the need for a longlived power source for implantable pacemakers. The first pacemakers were powered by a chemical (mercury–zinc) battery that lasted approximately 18 months, leading to the need for frequent replacement. The electronic power from a nuclear pacemaker comes from utilizing the heat from the decaying plutonium and converting it into electricity. Because the radioisotope has a half-life of 87.7 years, generators should remain active for decades. An 83-year-old man with an unknown past medical history was found minimally responsive at home. During EMS evaluation, he was noted to have a pacemaker generator in his left subclavian area. Shortly thereafter, the patient lost consciousness, became pulseless, and was found to be in asystole. Pulse and ventricular escape rhythm returned after treatment with epinephrine and atropine. The patient was intubated, and hemodynamic stability was achieved after emergent placement of a temporary transvenous pacemaker. Chest x-ray film revealed fracture of the single ventricular

AN ASSESSMENT OF THE PERFORMANCE OF PRE-PARTICIPATION GUIDELINES APPLIED TO NOVICE OLDER ENDURANCE ATHLETES

Despite robust growth in participation in marathons and endurance sports among older individuals, there is a lack of uniform recommendations for pre-participation cardiovascular evaluation (PPE) of these athletes. we evaluated the performance of 2 current PPE guidelines on a sample of novice runners

ARE YEARS OF TRAINING AN INDEPENDENT PREDICTOR OF ATRIAL FIBRILLATION IN OLDER RUNNERS

Accumulating data supports a relationship between long-term participation in distance running and atrial fibrillation (AF). In the present study we assessed whether accumulated years of running were related to reported AF and whether this relationship was independent of traditional risk factors for

Use of observation followed by outpatient stress testing in chest pain patients with prior coronary artery disease history: An evaluation of prognostic utility

Objective To determine the outcomes of patients with chest pain (CP) and prior history of coronary artery disease (CAD) managed with observation followed by outpatient stress myocardial perfusion imaging (MPI). Methods Retrospective analysis of patients with CP managed with observation followed by outpatient stress MPI, comparing cardiovascular (CV) event rates stratified by CAD history. Results 375 patients were included: 111 with and 264 without a CAD history. All patients underwent outpatient stress MPI within 72 h of observation. MPI identified patients at risk for CV events. However, while patients with negative MPI and without a CAD history had very low rates of short- and long-term CAD events (0.8%, 0.8%, and 1.3% at 30 days, 1 year, and 3 years, respectively), event rates of those with a negative test but a CAD history were significantly higher (2.6%, 5.3%, and 6.6% at 30 days, 1 year and 3 years, respectively; p = 0.044 and p = 0.034 compared to CAD− patients at 1 year and 3 years, respectively). In a multivariable logistic regression model, a positive MPI proved to be an independent predictor of long-term CV events in patients with CP and prior CAD. Conclusion Observation followed by stress MPI can effectively risk stratify CP patients with prior CAD for CV risk. These patients are at increased risk of CV events even after a low-risk stress MPI study. Patients presenting with CP and managed with a strategy of observation followed by a negative stress MPI warrant close short- and long-term monitoring for recurrent events.

ARE CARDIOVASCULAR RISK FACTORS RESPONSIBLE FOR THE U-SHAPED RELATIONSHIP BETWEEN RUNNING AND LONGEVITY? THE MASTERS ATHLETIC STUDY

Recent studies have noted a U-shaped relationship between running and longevity. While running was generally associated with increased lifespan, those who ran >20 miles per week did not experience a longer lifespan vs non-runners, possibly due to detrimental cardiac effects of higher mileage