Spontaneous Coronary Artery Dissection in a Male Patient With Fibromuscular Dysplasia.

A male patient presented with cardiac arrest attributed to anterior ST-segment elevation myocardial infarction from type 1 spontaneous coronary artery dissection. Subsequent imaging confirmed fibromuscular dysplasia in noncoronary arterial segments. The patient was started on guideline-directed medical therapy and referred to cardiac rehabilitation, showing substantial improvements in clinical status. With greater awareness and advancements in imaging, spontaneous coronary artery dissection has been more frequently recognized, and although as many as 81% to 92% of all cases occur in female patients, it can be seen among men, as well. Adjunctive imaging for arteriopathies may help establish the diagnosis for equivocal causes of acute coronary syndrome in women and men.

High Baseline High-Sensitivity Cardiac Troponin T Concentrations and Risk of Index Acute Myocardial Infarction.

OBJECTIVE: To evaluate the diagnostic performance of the previously recommended baseline high-sensitivity cardiac troponin T (hs-cTnT) thresholds of 52 and 100 ng/L in identifying patients at high risk of acute myocardial infarction (AMI). PATIENTS AND METHODS: This study compared the positive predictive value (PPV) for index AMI of these high-risk hs-cTnT thresholds in adult patients in the emergency department undergoing hs-cTnT measurement. RESULTS: The adjudicated MAyo Southwest Wisconsin 5th Gen Troponin T ImplementatiON cohort included 2053 patients, with 157 (7.6%) who received a diagnosis of AMI. The hs-cTnT concentrations of greater than 52 and greater than 100 ng/L resulted in PPVs of 41% (95% CI, 35%-48%) and 57% (95% CI, 48%-66%). In patients with chest discomfort, hs-cTnT concentrations greater than 52 ng/L resulted in a PPV of 66% (95% CI, 56%-76%) and hs-cTnT concentrations greater than 100 ng/L resulted in a PPV of 77% (95% CI, 65%-87%). The CV Data Mart Biomarker cohort included 143,709 patients, and 3003 (2.1%) received a diagnosis of AMI. Baseline hs-cTnT concentrations greater than 52 and greater than 100 ng/L resulted in PPVs of 12% (95% CI, 11%-12%) and 17% (95% CI, 17%-19%), respectively. In patients with chest pain and hs-cTnT concentrations greater than 52 ng/L, the PPV for MI was 17% (95% CI, 15%-18%) and in those with concentrations greater than 100 ng/L, only 22% (95% CI, 19%-25%). CONCLUSION: In unselected patients undergoing hs-cTnT measurement, the hs-cTnT thresholds of greater than 52 and greater than 100 ng/L provide suboptimal performance for identifying high-risk patients. In patients with chest discomfort, an hs-cTnT concentration of greater than 100 ng/L, but not the European Society of Cardiology-recommended threshold of greater than 52 ng/L, provides an acceptable performance but should be used only with other clinical features.

Validation of prediction tools for GI bleeding in patients on dual anti-platelet therapy after percutaneous coronary intervention.

BACKGROUND AND AIMS: The management of dual anti-platelet therapy after percutaneous coronary intervention (PCI) and GI bleeding (GIB) remains a clinical dilemma. We sought to identify predictors of GIB and recurrent bleeding and to determine whether recurrent bleeding increases the risk of major adverse cardiovascular events (MACEs). METHODS: In this single-center retrospective study, patients undergoing PCI were identified. The primary and secondary endpoints were GIB at 180 days and recurrent bleeding or MACE at 365 days. Logistic regression was used to identify predictors of GIB and recurrent bleeding. Cox proportional hazards modeling was used to determine whether recurrent bleeding can predict a MACE. RESULTS: Five hundred thirty-six patients were included. On multivariable analysis, PCI for acute coronary syndrome was associated with a 95% increased odds of GIB (P < .001). The P2Y12 inhibitor was continued in >90% of patients, which trended toward significance for recurrent bleeding (P < .10). The HAS-BLED score (Hypertension, Abnormal renal and liver function, Stroke, Bleeding tendency or predisposition, Labile INRs, Elderly, Drugs), including a labile international normalized ratio and prior major bleeding, was strongly associated with recurrent bleeding (P ≤ .009). Recurrent bleeding was associated with a 115% increased risk of MACEs (P = .02). We derived a novel risk score, named the SIGE score ([S]TEMI at PCI, having a labile [I]NR at PCI, index [G]IB within 180 days of PCI, and previous precatheterization [E]ndoscopy within 6 months), to predict recurrent bleeding at 365 days with a high predictive accuracy (area under the curve, .773; 95% confidence interval, .702-.845). CONCLUSIONS: The SIGE score may help to predict recurrent bleeding, which was shown to be associated with an increased risk of MACEs. Further external validation is needed.

Nonatheromatous Coronary Kink Causing Angiographic Obstruction: A Rare Structural Anomaly.

Ischemic symptoms may be explained by a multitude of coronary pathologies, including coronary artery tortuosity, atherosclerosis, fibromuscular dysplasia, vasculitis, coronary vasospasm, or microvascular disease. We present an unusual case of coronary kinking in a patient presenting with exertional jaw pain in the absence of atherosclerotic risk factors. Multimodality imaging, coronary imaging, and coronary physiology helped establish the diagnosis and guide management.

Association of Neurohormonal Antagonists on Incident Cardiotoxicity in Patients With Breast Cancer.

Cardiovascular disease is the leading cause of mortality among breast cancer survivors. Anthracyclines and trastuzumab have been associated with an increased risk of cardiotoxicity, requiring close follow-up for signs of clinical heart failure or asymptomatic left ventricular systolic dysfunction. Whether neurohormonal antagonism with angiotensin-converting enzyme inhibitor (ACE-I), angiotensin receptor blockers (ARBs), or ß-blockers can prevent the development of chemotherapy-induced cardiomyopathy in this population remains unknown. We studied 459 women who were diagnosed with breast cancer at our medical center from January 2014 to December 2021 and evaluated baseline characteristics, oncologic treatment, and outcomes. The primary end point was the development of cardiotoxicity, defined as symptomatic decline in ejection fraction of ≥5% below 55% or an asymptomatic decline of ≥10% after treatment with chemotherapy. Patients who were exposed to neurohormonal antagonists were more likely to have hypertension, hyperlipidemia, and diabetes. There was an increased risk of cardiotoxicity noted for patients who were older (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.01 to 1.1), smokers within the past 10 years (HR 2.54, 95% CI 1.41 to 4.6), or who received a combination of both trastuzumab and anthracycline therapy (HR 2.52, 95% CI 1.01 to 6.3). Over a median follow-up of 12 months, there were no significant protective benefits noted for patients who were taking ACE-I/ARBs (HR 0.49, 95% CI 0.17 to 1.4), ß-blockers (HR 0.50, 95% CI 0.16 to 1.6), or both (HR 1.30, 95% CI 0.44 to 3.9). In conclusion, previous use of ACE-I/ARBs and ß-blockers, separately or in combination, was not associated with a reduction in the development of cardiotoxicity in patients receiving anthracycline or trastuzumab therapies. Older age, smoking, and combination chemotherapy were found to be associated with an increased risk.

Rapid Exclusion of Acute Myocardial Injury and Infarction With a Single High-Sensitivity Cardiac Troponin T in the Emergency Department: A Multicenter United States Evaluation.

BACKGROUND: There are good data to support using a single high-sensitivity cardiac troponin T (hs-cTnT) below the limit of detection of 5 ng/L to exclude acute myocardial infarction. Per the US Food and Drug Administration, hs-cTnT can only report to the limit of quantitation of 6 ng/L, a threshold for which there are limited data. Our goal was to determine whether a single hs-cTnT below the limit of quantitation of 6 ng/L is a safe strategy to identify patients at low risk for acute myocardial injury and infarction. METHODS: The efficacy (proportion identified as low risk based on baseline hs-cTnT<6 ng/L) of identifying low-risk patients was examined in a multicenter (n=22 sites) US cohort study of emergency department patients undergoing at least 1 hs-cTnT (CV Data Mart Biomarker cohort). We then determined the performance of a single hs-cTnT<6 ng/L (biomarker alone) to exclude acute myocardial injury (subsequent hs-cTnT >99th percentile in those with an initial hs-cTnT<6 ng/L). The clinically intended rule-out strategy combining a nonischemic ECG with a baseline hs-cTnT<6 ng/L was subsequently tested in an adjudicated cohort in which the diagnostic performance for ruling out acute myocardial infarction and safety (myocardial infarction or death at 30 days) were evaluated. RESULTS: A total of 85 610 patients were evaluated in the CV Data Mart Biomarker cohort, among which 24 646 (29%) had a baseline hs-cTnT<6 ng/L. Women were more likely than men to have hs-cTnT<6 ng/L (38% versus 20%, P<0.0001). Among 11 962 patients with baseline hs-cTnT<6 ng/L and serial measurements, only 1.2% developed acute myocardial injury, resulting in a negative predictive value of 98.8% (95% CI, 98.6-99.0) and sensitivity of 99.6% (95% CI, 99.5-99.6). In the adjudicated cohort, a nonischemic ECG with hs-cTnT<6 ng/L identified 33% of patients (610/1849) as low risk and resulted in a negative predictive value and sensitivity of 100% and a 30-day rate of 0.2% for myocardial infarction or death. CONCLUSIONS: A single hs-cTnT below the limit of quantitation of 6 ng/L is a safe and rapid method to identify a substantial number of patients at very low risk for acute myocardial injury and infarction.

Characteristics and Outcomes After Transcatheter Aortic Valve Implantation in Immunocompromised Patients.

Immunocompromised (IC) patients are at greater risk of adverse outcomes from cardiac surgery, and less invasive options for treating severe aortic stenosis among IC patients are often sought. However, despite greater preference for transcatheter aortic valve implantation (TAVI) in this population, there are limited data on outcomes in IC patients. Between January 2015 and December 2019, we studied patients with severe aortic stenosis who underwent TAVI. We defined IC status by the presence of active malignancy and receipt of oncologic treatment, post-organ transplantation-associated immunosuppression, human immunodeficiency virus, chronic steroid use (>5 mg/day), or active autoimmune disorder, and compared characteristics and outcomes of IC patients with those of non-IC patients. Of 173 patients who underwent TAVI, 56 (32%) were IC, 30 (54%) had active malignancy and underwent active treatment, 19 (34%) were IC without malignancy, and 7 (13%) were both IC and had active malignancy. IC patients, compared with non-IC patients, had similar baseline demographics, Society of Thoracic Surgeons risk scores (median 4.3% vs 4.4%), and overall complications (29% vs 26%). There were 37 deaths (16 IC and 21 non-IC) over a median follow-up of 17 months (95% confidence interval [CI] 14 to 20 months), and 1-year survival after TAVI was 84.0% for IC patients and 89.0% for non-IC patients (p = 0.51 by log-rank). After adjusting for Society of Thoracic Surgeons risk scores, IC patients had a nonsignificant trend toward greater risk of death compared with non-IC patients (adjusted hazard ratio 1.48, 95% CI 0.77 to 2.84). IC patients had a significantly smaller risk of cardiac-related death (adjusted hazard ratio 0.21, 95% CI 0.05 to 0.98) but a greater risk of noncardiac-related death (adjusted hazard ratio 4.14, 95% CI 1.71 to 10.0) than non-IC patients. In conclusion, IC patients who underwent TAVI have similar complication rates as non-IC patients, with a nonsignificant trend toward greater mortality, specifically related to noncardiac causes.

Electrocardiographic markers of cardiac resynchronization therapy response: delayed time to intrinsicoid deflection onset in lateral leads.

Cardiac resynchronization therapy (CRT) has emerged as an important intervention for patients with heart failure (HF) with reduced ejection fraction and delayed ventricular activation. In these patients, CRT has demonstrated to improve quality of life, promote reverse left ventricular (LV) remodeling, reduce HF hospitalizations, and extend survival. However, despite advancements in our understanding of CRT, a significant number of patients do not respond to this therapy. Several invasive and non-invasive parameters have been assessed to predict response to CRT, but the electrocardiogram (ECG) has remained as the prevailing screening method albeit with limitations. Ideally, an accurate, simple, and reproducible ECG marker or set of markers would dramatically overcome the current limitations. We describe the clinical utility of an old ECG parameter that can estimate ventricular activation delay: the onset to intrinsicoid deflection (ID). Based on the concept of direct measurement of ventricular activation time (intrinsic deflection onset), time to ID onset measures on the surface ECG the time that the electrical activation time takes to reach the area subtended by the corresponding surface ECG lead. Based on this principle, the time to ID on the lateral leads can estimate the delay activation to the lateral LV wall and can be used as a predictor for CRT response, particularly in patients with non-specific intraventricular conduction delay or in patients with left bundle branch block and QRS < 150 ms. The aim of this review is to present the current evidence and potential use of this ECG parameter to estimate LV activation and predict CRT response.

Factors associated with change in frailty scores and long-term outcomes in older adults with coronary artery disease.

OBJECTIVE: Older adults with coronary artery disease (CAD) are at risk for frailty. However, little is known regarding transition in frailty measures over time or its impact on outcomes. We sought to determine the association of temporal change in frailty with long-term outcome in older adults with CAD. METHODS: We re-assessed for phenotypic frailty using the Fried index (0 = not frail; 1-2 = pre-frail; ≥ 3 frail) in a cohort of CAD patients ≥ 65 years old at 2 time points 5 years apart. Factors associated with frailty worsening were assessed with scatterplots and outcomes estimated using the Kaplan-Meier method. Cox models were used to assess the risk of worsening frailty on outcome. RESULTS: There were 45 subjects that completed both baseline and 5-year Fried frailty assessment. Mean age was 74.6 ± 5.9 and 30 (67%) were men. Frailty incidence increased over time: baseline (3% frail, 37% pre-frail); 5 years (10% frail, 40% pre-frail). Baseline factors were not predictors of worsening frailty score, while both slower walk time (r = 0.46; P = 0.004) and diminishing grip strength (r = -0.39; P = 0.01) were associated with worsening frailty transitions. In follow-up (median 5.2 years), long-term major adverse cardiac event (MACE) free survival (P = 0.12) or hospitalization (P = 0.98) was not different for those with worsening frailty score (referent: improved/unchanged frailty). Frailty worsening had a trend towards increased risk of MACE (HR = 1.86; 95% CI: 0.65-5.27, P = 0.25). CONCLUSIONS: Frailty transitions, specifically, declines in walk time and grip strength, were strongly associated with worsening frailty score in a cohort of older adults with CAD than were baseline indices, though frailty change status was not independently associated with MACE outcomes.

Fluorescent angiography used as a tool to guide angiosome-directed endovascular therapy for diabetic foot ulcers.

Angiosome-directed endovascular therapy for the treatment of chronic limb-threatening ischemia (CLTI) remains controversial owing to the overlap of wound angiosomes. Angiographic grading of success has limitations and translesional pressure assessments are seldom performed in the infrapopliteal vessels. Objective criteria to determine revascularization success in tibiopedal vessels have not been well described. Quantifying perfusion to a wound bed after establishing direct or indirect (via collateral) flow after revascularization is an important component for treating CLTI patients yet is seldom performed. We report the use of fluorescent angiography to quantitatively examine perfusion of a diabetic foot ulcer before and after angiosome-directed endovascular therapy.

Poor quality of life in patients with and without frailty: co-prevalence and prognostic implications in patients undergoing percutaneous coronary interventions and cardiac catheterization.

AIMS: We hypothesize that poor quality of life (QOL) is highly prevalent in frail older adults and is associated with worse prognosis. METHODS AND RESULTS: Predismissal standardized tests for frailty and QOL were prospectively administered to patients included in two cohorts. In Cohort 1, 629 patients ≥65 years who underwent percutaneous coronary intervention (PCI) from 2005 to 2008, frailty (Fried criteria), and QOL [SF-36 and Seattle Angina Questionnaires (SAQ)] were ascertained. Cohort 2 included 921 patients ≥55 years who underwent cardiac catheterization (535 had PCI) from 2014 to 2018 and frailty was determined by Rockwood criteria and QOL by single-item, self-reported health questionnaire. In Cohort 1, 19% were frail and 20% patients in Cohort 2 were frail with a frailty index >0.30. The median SAQ for physical limitation (58.9 vs. 82.2, P < 0.001), physical (29.5 vs. 43.9, P < 0.001), and mental (49.2 vs. 57.4, P < 0.001) component scores of SF-36 in Cohort 1 were lower and self-rating of fair/poor health (56% vs 18%, P < 0.001) in Cohort 2 was significantly higher in frail patients. As compared to patients without frailty, frail patients were five times more likely (59% vs. 11%, P < 0.001) in Cohort 1 and seven times more likely (56% vs. 8%) in Cohort 2 to be classified with poor QOL. Age- and gender-adjusted 3-year all-cause death and death or myocardial infarction (MI) was significantly higher for patients undergoing PCI with frailty; [hazard ratio (95% confidence interval) death, 4.20 (2.63-6.68, P < 0.001) and death or MI hazard ratio (HR) 2.72 (1.91-3.87, P < 0.001)] and with poor QOL [HR death 2.47 (1.59-3.84, P < 0.001)] and death or MI 1.61 (1.16-2.24, P < 0.001). There was no significant interaction between frailty and QOL (P = 0.64) and only modest attenuation was observed when considered together indicating their independent prognostic influence. CONCLUSION: In elderly patients undergoing cardiac catheterization or PCI, poor QOL is seen more frequently in frail patients. Both frailty and poor QOL had significant and independent association with long-term survival.

Familial Tako-tsubo Cardiomyopathy: Clinical and Echocardiographic Features Including Magnetic Resonance Imaging Findings.

INTRODUCTION: Tako-tsubo cardiomyopathy (TCM) is being recognized more frequently; and a familial form of this diagnosis has been suspected but is less well-established. CASE: A 75-year-old patient with a family history of TCM was admitted with suspected ST-segment elevation myocardial infarction. Transthoracic echocardiography showed apical dyskinesis with hyperdynamic basal walls and a left ventricular ejection fraction (LVEF) of 25%. Repeat echocardiography showed normal LVEF of 60% ejection fraction. Cardiac catheterization showed no significant stenosis. DISCUSSION: TCM is characterized by transient systolic left ventricular dysfunction. A few cases of familial TCM have been reported in the literature and a genetic component is suspected. CONCLUSIONS: Although there has been a paucity of data, familial cases of TCM have been reported. This case study addresses TCM and the familial occurrence of the syndrome, which may have a genetic basis.

Fragmentation of QRS complex during ventricular pacing is associated with ventricular arrhythmic events in patients with left ventricular dysfunction.

BACKGROUND: QRS fragmentation (fQRS) during baseline ventricular conduction, a myocardial fibrosis marker, is associated with increased risk of ventricular tachyarrhythmias but may not manifest unless ventricular activation change is provoked. We examined the association of fQRS during right ventricular (RV) pacing with death and ventricular tachyarrhythmia in patients with left ventricular (LV) dysfunction undergoing electrophysiology study (EPS). METHODS AND RESULTS: Study participants had LV dysfunction (ejection fraction < 50%) undergoing EPS from January 2002 to May 2014 at Mayo Clinic in Rochester, Minnesota. fQRS during RV stimulation involved >2 notches on R/S waves identified in ≥2 contiguous standard electrocardiographic leads representing anterior, inferior, or lateral ventricular segments. Primary outcomes were ventricular tachyarrhythmias that were symptomatic or required intervention and total and cardiac deaths. In all, 528 patients participated (mean age, 65 years; male sex, 80%). Of them, 312 (59%) had ischemic cardiomyopathy and mean (SD) left ventricular ejection fraction (LVEF) of 33.2% (9.5%); 457 (87%) had implantable cardiac devices (implanted defibrillator, n  =  380). Mean (SD) follow-up was 3.2 (3.0) years. fQRS during RV pacing was observed in 292 patients (60%) in any ventricular segment. Patients with fQRS during RV pacing had 2.5 higher rate of ventricular tachyarrhythmia events than patients with no fQRS (hazard ratio [95% CI], 2.45 [1.5-4.2]; P < 0.01), after correcting for baseline ventricular conduction defect and QRS duration, LVEF, inducible sustained ventricular tachycardia, diabetes mellitus, chronic kidney disease, and ischemic cardiomyopathy. CONCLUSIONS: RV stimulation can unmask fQRS, and it is associated with increased risk of ventricular tachyarrhythmia in LV dysfunction.

Characteristics and long term outcomes of patients with acute coronary syndromes due to culprit left main coronary artery disease treated with percutaneous coronary intervention.

BACKGROUND: Patients with acute coronary syndrome (ACS) due to unprotected culprit left main coronary artery disease (LMCAD) treated with percutaneous coronary intervention (PCI) are rare, high-risk, and not represented in trials. Data regarding long term outcome after PCI are limited. METHODS: Between January 2000 and December 2014, there were 8,794 patients hospitalized with unstable angina/non-ST elevation myocardial infarction (UA/NSTEMI) or ST-elevation myocardial infarction (STEMI) treated with PCI at our institution; of these, 83 (0.94%) patients were identified as having culprit LMCAD ACS. RESULTS: Of the 83 patients with unprotected LMCAD ACS, 40 patients presented with STEMI and 43 patients presented with UA/NSTEMI. As compared to LM UA/NSTEMI, LM STEMI patients were younger and had less hypertension, with a trend towards greater frequency of cardiogenic shock. Distal LM involvement was common in both groups and did not differ by ACS type. In-hospital mortality was 33% in LM STEMI and 9% in LM UA/NSTEMI (P = .009). Over median follow up of 6.3 years, long term survival rates in both groups were similar (46% for STEMI vs 51% for UA/NSTEMI; P = .50 by log-rank). CONCLUSIONS: Unprotected culprit LMCAD ACS necessitating PCI is uncommon, occurring in <1% of cases, but is associated with reduced survival, with long term follow-up noting continued and similar risk of death regardless of index ACS type.

ST-Segment Elevation Myocardial Infarction and Normal Coronary Arteries after Consuming Energy Drinks.

The use of energy drinks, which often contain stimulants, is common among young persons, yet there have been few reports of adverse cardiac events. We report the case of a 27-year-old man who was admitted to our facility with an acute ST-segment elevation myocardial infarction in the setting of using energy drinks. Angiography revealed no obstructive coronary disease. The patient had elevation of cardiac troponin. Noninvasive testing with echocardiography and cardiac magnetic resonance imaging demonstrated both abnormalities in resting wall motion at the anterior apex along with late gadolinium enhancement of the anterior wall, respectively. The patient also underwent formal invasive evaluation with an intracoronary Doppler study demonstrating normal coronary flow reserve and acetylcholine provocation that excluded endothelial dysfunction and microvascular disease. The patient recovered and has abstained from consuming additional energy drinks with no reoccurrence of symptoms. A review of some of the potential cardiac risks associated with consuming energy drinks is presented.

Outcomes of Physician-Staffed Versus Non-Physician-Staffed Helicopter Transport for ST-Elevation Myocardial Infarction.

BACKGROUND: The effect of physician-staffed helicopter emergency medical service (HEMS) on ST-elevation myocardial infarction (STEMI) patient transfer is unknown. The purpose of this study was to evaluate the characteristics and outcomes of physician-staffed HEMS (Physician-HEMS) versus non-physician-staffed (Standard-HEMS) in patients with STEMI. METHODS AND RESULTS: We studied 398 STEMI patients transferred by either Physician-HEMS (n=327) or Standard-HEMS (n=71) for primary or rescue percutaneous coronary intervention at 2 hospitals between 2006 and 2014. Data were collected from electronic medical records and each institution's contribution to the National Cardiovascular Data Registry. Baseline characteristics were similar between groups. Median electrocardiogram-to-balloon time was longer for the Standard-HEMS group than for the Physician-HEMS group (118 vs 107 minutes; P=0.002). The Standard-HEMS group was more likely than the Physician-HEMS group to receive nitroglycerin (37% vs 15%; P<0.001) and opioid analgesics (42.3% vs 21.7%; P<0.001) during transport. In-hospital adverse outcomes, including cardiac arrest, cardiogenic shock, and serious arrhythmias, were more common in the Standard-HEMS group (25.4% vs 11.3%; P=0.002). After adjusting for age, sex, Killip class, and transport time, patients transferred by Standard-HEMS had increased risk of any serious in-hospital adverse event (odds ratio=2.91; 95% CI=1.39-6.06; P=0.004). In-hospital mortality was not statistically different between the 2 groups (9.9% in the Standard-HEMS group vs 4.9% in the Physician-HEMS group; P=0.104). CONCLUSIONS: Patients with STEMI transported by Standard-HEMS had longer transport times, higher rates of nitroglycerin and opioid administration, and higher rates of adjusted in-hospital events. Efforts to better understand optimal transport strategies in STEMI patients are needed.

Prolonged Ventricular Conduction and Repolarization During Right Ventricular Stimulation Predicts Ventricular Arrhythmias and Death in Patients With Cardiomyopathy.

OBJECTIVES: The goal of this study was to evaluate whether prolonged ventricular conduction (paced QRS) and repolarization (paced QTc) times observed during ventricular stimulation predict ventricular arrhythmic events and death. BACKGROUND: Abnormal ventricular conduction and repolarization can predispose patients to ventricular arrhythmias. METHODS: Consecutive patients with left ventricular dysfunction (ejection fraction <50%) undergoing electrophysiology studies from January 2002 until May 2014 were identified at Mayo Clinic (Rochester, Minnesota). Patients were followed up until December 2014 for occurrence of ventricular arrhythmias and death. RESULTS: Among the 501 patients included (mean age 65 years; mean left ventricular ejection fraction 33.1%), longer paced ventricular conduction was associated with longer baseline QRS duration, longer QT interval, and lower ejection fraction. On multivariable analysis, longer paced QRS duration was associated with higher risk of ventricular arrhythmia (hazard ratio [HR]: 1.11 per 10-ms increase; 95% confidence interval [CI]: 1.07 to 1.16; p < 0.001) and all-cause death or arrhythmia (HR: 1.09; 95% CI: 1.09 to 1.13; p < 0.001). A paced QRS duration >190 ms was associated with a 3.6 times higher risk of ventricular arrhythmia (HR: 3.6; 95% CI: 2.35 to 5.53; p < 0.001) and a 2.1 times higher risk of death or arrhythmia (HR: 2.12; 95% CI: 1.53 to 2.95; p < 0.001), independent of left ventricular function or baseline QRS duration. Longer QTc interval during ventricular pacing was associated with a higher risk of ventricular arrhythmia (HR: 1.03 per 10-ms increase; 95% CI: 1.02 to 1.12; p < 0.001) independent of paced QRS duration. CONCLUSIONS: Longer paced QRS duration and paced QTc interval predict ventricular arrhythmias in patients with cardiomyopathy. Ventricular conduction and repolarization prolongation during right ventricular pacing can determine the risk of ventricular arrhythmias.