In any claim for compensation for injury or death from cardiovascular or cerebral vascular causes, the claimant shall prove by a preponderance of the credible evidence that the injury or death was produced by the work effort or strain involving a substantial condition, event or happening in excess of the wear and tear of the claimant's daily living and in reasonable medical probability caused in a material degree the cardiovascular or cerebral vascular injury or death resulting therefrom.
Material degree means an appreciable degree or a degree substantially greater than de minimis.
N.J.S. § 34:15-7.2