First and recurrent events after percutaneous coronary intervention: implications for survival analyses.

Objectives. Using composite endpoints and/or only first events in clinical research result in information loss and alternative statistical methods which incorporate recurrent event data exist. We compared information-loss under traditional analyses to alternative models. Design. We conducted a retrospective analysis of patients who underwent percutaneous coronary intervention (Jan2010-Dec2014) and constructed Cox models for a composite endpoint (readmission/death), a shared frailty model for recurrent events, and a joint frailty (JF) model to simultaneously account for recurrent and terminal events and evaluated the impact of heart failure (HF) on the outcome. Results. Among 4901 patients, 2047(41.8%) experienced a readmission or death within 1 year. Of those with recurrent events, 60% had ≥1 readmission and 6% had >4; a total of 121(2.5%) patients died during follow-up. The presence of HF conferred an adjusted Hazard ratio (HR) of 1.32 (95% CI: 1.18-1.47, p < .001) for the risk of composite endpoint (Cox model), 1.44 (95% CI: 1.36-1.52, p < .001) in the frailty model, and 1.34 (95% CI:1.22-1.46, p < .001) in the JF model. However, HF was not associated with death (HR 0.87, 95% CI: 0.52-1.48, p = .61) in the JF model. Conclusions. Using a composite endpoint and/or only the first event yields substantial loss of information, as many individuals endure >1 event. JF models reduce bias by simultaneously providing event-specific HRs for recurrent and terminal events.

Event dependence in the analysis of cardiovascular readmissions postpercutaneous coronary intervention.

Recurrent hospitalizations are common in longitudinal studies; however, many forms of cumulative event analyses assume recurrent events are independent. We explore the presence of event dependence when readmissions are spaced apart by at least 30 and 60 days. We set up a comparative framework with the assumption that patients with emergency percutaneous coronary intervention (PCI) will be at higher risk for recurrent cardiovascular readmissions than those with elective procedures. A retrospective study of patients who underwent PCI (January 2008-December 2012) with their follow-up information obtained from a regional database for hospitalization was conducted. Conditional gap time (CG), frailty gamma (FG) and conditional frailty models (CFM) were constructed to evaluate the dependence of events. Relative bias (%RB) in point estimates using CFM as the reference was calculated for comparison of the models. Among 4380 patients, emergent cases were at higher risk as compared with elective cases for recurrent events in different statistical models and time-spaced data sets, but the magnitude of HRs varied across the models (adjusted HR [95% CI]: all readmissions [unstructured data]-CG 1.16 [1.09 to 1.22], FG 1.45 [1.33 to 1.57], CFM 1.24 [1.16 to 1.32]; 30-day spaced-CG1.14 [1.08 to 1.21], FG 1.28 [1.17 to 1.39], CFM 1.17 [1.10 to 1.26]; and 60-day spaced-CG 1.14 [1.07 to 1.22], FG 1.23 [1.13 to 1.34] CFM 1.18 [1.09 to 1.26]). For all of the time-spaced readmissions, we found that the values of %RB were closer to the conditional models, suggesting that event dependence dominated the data despite attempts to create independence by increasing the space in time between admissions. Our analysis showed that independent of the intercurrent event duration, prior events have an influence on future events. Hence, event dependence should be accounted for when analyzing recurrent events and challenges contemporary methods for such analysis.

Major Adverse Renal and Cardiac Events After Coronary Angiography and Cardiac Surgery.

BACKGROUND: Patients at high risk for having postprocedural complications may receive iodixanol, an iso-osmolar contrast, during coronary angiography to minimize the risk of renal toxicity. For those who also require cardiac surgery, the wait time between angiography and surgery may be a modifiable factor capable of mitigating poor surgical outcomes; however, there have been inconsistent reports regarding the optimal wait time. We sought to determine the effects of wait time between angiography and cardiac surgery, as well as contrast-induced acute kidney injury on the development of major adverse renal and cardiac events (MARCE). METHODS: We merged datasets to identify adults who underwent coronary angiography with iodixanol and subsequent cardiac surgery. RESULTS: Of 965 patients, 126 (13.1%) had contrast-induced acute kidney injury; 133 (13.8%) had MARCE within 30 days and 253 (26.2%) within 1 year of surgery. After adjusting for contrast-induced acute kidney injury, age, and Thakar acute renal failure score, the effect of wait time lost significance for the full cohort, but remained for the subgroup of 654 who had coronary artery bypass graft surgery. Patients undergoing coronary artery bypass graft surgery within 1 day of coronary angiography had an approximate twofold increase in risk of MARCE (30-day hazard ratio 2.13, 95% confidence interval: 1.16 to 3.88, p = 0.014; 1-year hazard ratio 2.07, 95% confidence interval: 1.32 to 3.23, p = 0.002) compared with patients who waited 5 or more days. CONCLUSIONS: Patients who had contrast-induced acute kidney injury and had cardiac surgery within 1 day of angiography had an increased risk of MARCE.

Right atrial thrombus and its causes, complications, and therapy.

A 70-year-old man who presented with dyspnea and intermittent chest pain was found to have a large free-floating right atrial thrombus on two-dimensional echocardiogram. Atriotomy was performed, and an 18-cm-long thrombus was removed from the right atrium and inferior vena cava. Postoperatively, the patient developed cardiogenic shock treated by intravenous vasopressor agents and extracorporeal membrane oxygenation. The postoperative course was also complicated by bilateral pulmonary emboli requiring pulmonary artery thrombectomy. Right atrial thrombus is an underdiagnosed condition with a high mortality rate. The best management modality has not yet been established.

Contrast-Induced Acute Kidney Injury.

Coronary angiography and percutaneous intervention rely on the use of iodinated intravascular contrast for vessel and chamber imaging. Despite advancements in imaging and interventional techniques, iodinated contrast continues to pose a risk of contrast-induced acute kidney injury (CI-AKI) for a subgroup of patients at risk for this complication. There has been a consistent and graded signal of risk for associated outcomes including need for renal replacement therapy, rehospitalization, and death, according to the incidence and severity of CI-AKI. This paper reviews the epidemiology, pathophysiology, prognosis, and management of CI-AKI as it applies to the cardiac catheterization laboratory.

Critical lower limb ischemia from an embolized Angio-Seal closure device.

Vascular closure devices were introduced in the early 1990s in an effort to reduce time to hemostasis, enable early ambulation, and improve the comfort of patients undergoing femoral artery access for endovascular procedures. Many of these devices leave a foreign component in or around the artery, which can lead to complications such as hematoma, pseudoaneurysm, infection, or limb ischemia. Here we present a case where device embolization led to arterial occlusion and critical limb ischemia.

Frequency of atrial tachyarrhythmias following transcatheter closure of patent foramen ovale.

BACKGROUND: Transcatheter closure of patent foramen ovale (PFO) in patients with a history of cryptogenic stroke is performed with increasing frequency. However, the long-term effects of these closure devices on atrial tachyarrhythmias (ATs) are not known. METHODS AND RESULTS: The study population included 71 patients [31 (44%) men, aged 54 +/- 14 years] with PFO, diagnosed by transesophageal echocardiography (TEE), and greater than or equal to 1 cryptogenic stroke (n = 70) or orthodoxia (n = 1). Patients underwent transcatheter closure of PFO using a 28 mm (n = 53) or a 33 mm (n = 18) CardioSEAL closure device (n = 67) or an Amplatzer occluder (n = 4). Five (7%) patients presented with newly diagnosed (n = 4) or recurrent (n = 1) episodes of AT (3 atrial fibrillation and 2 typical atrial flutter) within 1 to 480 days following the procedure, with an average time to onset of 175 +/- 221 days. ATs were more frequent in those who received a 33 mm device than those who received a 28 mm device [4/18 (22%) vs. 1/53 (2%); p < 0.05]. Patients with ATs showed a trend toward a larger left atrium only on apical view (6.5 +/- 1.4 cm vs. 5.1 +/- 0.9 cm; p = 0.05). However, the difference in left atrial size on parasternal view and right atrial size between the 2 groups was not statistically significant (4.5 +/- 1.1 cm vs. 3.7 +/- 0.8 cm and 5.9 +/- 2.4 cm vs. 4.6 +/- 0.7 cm). Conclusion. Compared to the age-matched population, sustained ATs appear to be relatively common following transcatheter closure of PFO. In our series, they seemed to occur more frequently in patients who received larger devices.

Repeated dual external direct cardioversions using two simultaneous 360-J shocks for refractory atrial fibrillation are safe and effective.

Failure of cardioversion of atrial fibrillation (AF) to sinus rhythm (SR) by standard external direct current cardioversion (DCC) may be due to failure of delivery of enough defibrillating energy rather than to the true refractoriness of AF. Ninety-nine patients with persistent AF (76 male; age 63.7 +/- 0.4 years; weight 113.1 +/- 25.1 kg) who failed standard DCC were included in this report. Under anesthesia, QRS synchronous shocks were delivered across anteroposterior electrodes in the following sequence: (1) a single 360-J shock; (2) another single 360-J shock within 2 minutes; (3) 30 minutes of rest, reinduction of anesthesia and delivery of two simultaneous monophasic 360-J shocks. All patients underwent all three DCC steps. Sixty-six (67%) patients converted to SR following the first dual simultaneous shock. Fourteen patients (14%) required more than one dual shock to achieve SR. This increased the overall success rate of resuming SR to 81%. Except for minor skin burns in three patients there were no procedure related complications. On follow-up at 1 month, 55 (56%) patients were still in SR, whereas 50 (51%) patients maintained SR at 12 months. This was similar to our general DCC population (55% of the 1698 patients were in SR 6 months post-DCC, P = ns). In conclusion, dual external monophasic 360-J DCC is an effective rescue technique for restoration of SR in patients with AF refractory to standard DCC. AF in these patients seems to be as amenable to chronic suppression as AF in the general population of DCC patients.

Difficult cases in heart failure. Percutaneous transluminal septal myocardial ablation in the management of hypertrophic obstructive cardiomyopathy.

Hypertrophic cardiomyopathy is a complex genetic condition with a heterogeneous clinical course. Some patients remain asymptomatic throughout life while others develop one or more of the adverse clinical consequences including symptoms of congestive heart failure with exertional dyspnea and functional disability (usually with preserved left ventricular systolic function), atrial fibrillation, or sudden cardiac death. Because of this heterogenicity in the clinical presentations, management of patients with hypertrophic cardiomyopathy includes a wide range of pharmacologic therapies as well as invasive approaches. In recent years, nonsurgical catheter-based treatment of hypertrophic cardiomyopathy has been increasingly used in the management of a subset of these patients. The authors present a case of percutaneous transluminal septal myocardial ablation in a patient with hypertrophic cardiomyopathy who was symptomatic despite maximal medical treatment.