Residents of storm-ravaged New Orleans continue to have higher rates of myocardial infarction four years after the Hurricane Katrina struck. New data - an update to the researchers' two-year post-Hurricane Katrina analysis - show a persisting three-fold increase in acute myocardial infarction (AMI) along with other negative effects, according to research presented today at the American College of Cardiology's 60th Annual Scientific Session.

While previous studies have found increases in heart attacks and other cardiac events occurring in the immediate hours to weeks after major disasters such as earthquakes or volcano eruptions, authors say this is the first long-term retrospective analysis of this nature, and the first to investigate heart health in the aftermath of Hurricane Katrina.

"To our surprise, the persistent three-fold increase in heart attack risk has occurred in the absence of any change in traditional risk factors - for example, age, high blood pressure, obesity and diabetes," said Anand Irimpen, M.D., associate professor of medicine for the Heart and Vascular Institute at Tulane University School of Medicine Center and chief of cardiology of the Southeast Louisiana Veterans Health Care System. "We had some indication of Katrina's effect on heart health from our initial study, but it appears to be more far-reaching than expected. The factors we looked at two years ago have generally become more significant and new factors have emerged that appear to play a role in heart health."

While psychiatric co-morbidities (e.g., depression, schizophrenia, bipolar and anxiety disorder), a history of coronary artery disease and marital status did not appear to contribute to heart attacks in the two-year analysis, these factors seem to play a significant role as time has progressed. Irimpen supposes there might be a lag phase between the onset of psychiatric illness and its somatic manifestation in the form of a heart attack.

"Certainly chronic stress appears to play an ongoing role," Irimpen said. "It's leading to what I view as akin to a Post-Katrina Stress Disorder. Many of the patients we see are not yet back to their pre-Katrina residences, have not regained employment and are too stressed to pay attention to ideal health practices. They are more likely to smoke, overuse alcohol or other substances and are less likely to comply with treatment plans that can help prevent heart attacks."

In this single-center, retrospective, observational study, patients admitted with heart attacks to Tulane Medical Center in the two years before Katrina and the four years after the hospital reopened (five months after Katrina) were identified from hospital records. Researchers looked for differences in the incidence of heart attacks and compared the two groups (pre- and post-Katrina) based on specific demographic and clinical data (e.g., lab test results, health insurance, first-time hospitalization, medical non-adherence, smoking status, substance abuse, employment). In the post-Katrina group, there were 629 confirmed admissions for AMI, out of a total census of 29,228 patients (2.2 percent), as compared to 150 AMI admissions out of a total 21,229 patients (0.7 percent) in the pre-Katrina group (p<0.0001).

Compared to the pre-Katrina group, those experiencing a heart attack post-Katrina were more likely to be unemployed (17 percent vs. 2 percent, p<0.0001), lack medical insurance (12 percent vs. 6 percent, p<0.0001), smoke (58 percent vs. 17 percent, p<0.001), be less compliant with treatment plans (25 percent vs. 7 percent, p<0.0001) and report substance abuse (16 percent vs. 7 percent, p<0.01).

The post-Katrina group had more first time hospitalizations (32 percent vs. 17 percent, p<0.001), psychiatric comorbidities (10 percent vs. 6 percent, p<0.05), hyperlipidemia (45 percent vs. 52 percent, p=0.01), history of coronary artery disease (46 percent vs. 31 percent, p=0.001), and percutaneous coronary interventions (66 percent vs. 52 percent, p<0.0001). More people in the post-Katrina group were single or divorced (30 percent vs. 26 percent, p<0.05). Similar to the 2-year data, heart attack patients were more likely local residents rather than visitors (p<0.0001) or people living in temporary housing (p<0.0001). These differences were all statistically significant and the groups were comparable in terms of age, race, and gender, and history of hypertension, diabetes mellitus and chronic renal disease.

"As clinicians, we must pay closer attention to patients affected by Hurricane Katrina and other major disasters as they seem to have long-term and detrimental effects on the health of the community," Irimpen said. "We hope our findings will have enduring ramifications on improving surveillance, prevention efforts and cardiovascular care in New Orleans."